KRITERION JOURNAL OF PHILOSOPHY. Volume 30, Issue Special issue: New Developments in Philosophy of Time Guest edited by Florian Fischer

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1 KRITERION JOURNAL OF PHILOSOPHY Volume 30, Issue Special issue: New Developments in Philosophy of Time Guest edited by Florian Fischer Florian Fischer: Philosophy of time: A slightly opinionated introduction Jesse M. Mulder: Defining Original Presentism Florian Fischer: Carnap s Logic of Science and Reference to the Present Moment Cord Friebe: Time Order, Time Direction, and the Presentist s View on Spacetime Sonja Deppe: The Mind-Dependence of the Relational Structure of Time (or: What Henri Bergson Would Say to B-theorists) Pamela Zinn: Lucretius On Time and Its Perception

2 EDITORIAL KRITERION Journal of Philosophy is a forum for contributions in any field of analytic philosophy. We welcome submissions of previously unpublished papers, not under consideration for publication anywhere else. Submissions are reviewed in double-blind peer review mode. Contributions should meet the following conditions: (1) The content must be philosophical. (2) The language must be intelligible to a broader readership. (3) The contribution must contain a traceable argumentation. The length should be between 4000 and 8000 words. Only contributions in English (preferred) and German are accepted. IMPRESSUM Editors-in-Chief: Christian J. Feldbacher-Escamilla, Alexander Gebharter Editorial Board: Albert J. J. Anglberger, Laurenz Hudetz, Christine Schurz, Christian Wallmann Address: Franziskanergasse 1, 5020 Salzburg, Austria. editor@kriterion-journal-of-philosophy.org Web: Indexing: KRITERION Journal of Philosophy is indexed and abstracted by The Philosopher s Index and EBSCOhost Humanities Source. Information about the journal s ranking is available at SJR. The journal was also approved of satisfying the ERIH (European Reference Index for the Humanities) criteria: ERIH PLUS. Copyright: The copyright remains with the authors. ISSN:

3 Preface Florian Fischer The idea to make this special issue was born during the Tensed vs Tenseless Theory symposium ( at the SOPhiA conference in Salzburg There, also, the Society for Philosophy of Time (SPoT - was founded. During the subsequent SPoT discussion groups and workshops ( some of the papers of this volume have been presented, in one form or other. As this special issue corporealised the SPoT was growing. I m grateful to everybody who was part of this exiting journey, but especially I want to thank Christian J. Feldbacher- Escamilla and Alexander Gebharter from KRITERION Journal of Philosophy to make this special issue possible. As the SPoT is set up very broadly, this special issue aims at depicting philosophy of time in all of its varieties. After A Slightly Opinionated Introduction into philosophy of time, Jesse Mulder questions the set up of the eternalism/presentism debate in his Defining Original Presentism. His paper reflects the cutting edge of contemporary debate about the nature of time. Then, my paper touches upon the intersection of philosophy of time and philosophy of science, investigating the relation between Carnap s Logic of Science and Reference to the Present Moment. Cord Friebe s Time Order, Time Direction, and the Presentist s View on Spacetime covers the intersection between philosophy of physics and philosophy of time. The last part of the special issue has a more historical twist albeit still being systematic. Sonja Deppe s The Mind-Dependence of the Relational Structure of Time is concerned with more recent history (Henri Bergson), while Pamela Zinn s Lucretius On Time and Its Perception examines more ancient history. Florian Fischer University of Bonn Institut für Philosophie Am Hof Bonn <fischerf@uni-bonn.de> < Kriterion Journal of Philosophy, 2016, 30(2): c 2016 The author

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5 Philosophy of time: A slightly opinionated introduction Florian Fischer There are several intertwined debates in the area of contemporary philosophy of time. One field of inquiry is the nature of time itself. Presentists think that only the present moment exists whereas eternalists believe that all of (space-)time exists on a par. The second main field of inquiry is the question of how objects persist through time. The endurantist claims that objects are three-dimensional wholes, which persist by being wholly 1 present, whereas the perdurantist thinks that objects are fourdimensional and that their temporal parts are the bearers of properties. The third debate in the field of contemporary philosophy of time is about tense- versus tenseless theory. Tensers are at odds with detensers about the status of the linguistic reference to the present moment. These are only very crude characterizations and it is even disputed by some advocates of the corresponding positions that they are accurate. However this very sketchy picture already reveals a fundamental difference: The eternalism/presentism and endurance/perdurance discussions belong to the field of metaphysics, whereas tense is in the first instance a linguistic phenomenon. Among the many fields of philosophy, there are two that are more intimately interconnected than most but whose practitioners have too long pursued relatively independent paths. On the one hand, there are philosophers of language, who have devoted much attention to indexicals ( now, etc.), temporal operators ( it has been the case that, etc.), and tensed sentences. On the other hand, there are the philosophers of tensed and tenseless time (also called A-time or B-time, dynamic time or static time, etc.). [27, p. 1] Jokic and Smith s claim can be generalized for philosophy of time as a whole: There are prima facie distinct debates about the nature of time, the persistence of objects and the reference to the present moment. However these debates are interrelated and the position held regarding one of them may have implications upon the options for the other debates. Kriterion Journal of Philosophy, 2016, 30(2): c 2016 The author

6 4 KRITERION Journal of Philosophy, 2016, 30(2): 3 28 And even if systematic links between the debates have to be rejected, the choices in one debate often de facto mirror the choices in the others: the line between philosophy of language and metaphysics is blurred and, one is tempted to view them instead as a continuum [27, p. 3 4]. This introduction proceeds as follows: In section 1 the debate between eternalists and presentists is depicted. Section 2 then introduces the problem of change and the alleged solutions by the perdurantist and endurantist. The positions of the tense and tenseless theoreticians are presented in section 3. Lastly some inter-theoretical links and various package-deals are presented in section 4. 1 Eternalism/Presentism Eternalists and presentists debate about the nature of time. 2 While presentists think that the present is ontologically outstanding, eternalists hold that the whole (space-)time 3 is ontologically on a par or, put differently, according to the presentist, only present entities exist; according to the eternalist, past and future entities also exist [63, p. 256]. Main works of eternalists include David Lewis s On the Plurality of Worlds [32], Willard Van Orman Quine s Word & Object [57] and Ted Sider s Four-Dimensionalism [59]. Seminal contributions to the debate by presentists include Bigelow s Presentism and Properties [5], Ned Markosian s A Defence of Presentism [35], Trenton Merricks Persistence, Parts, and Presentism [43] and Dean Zimmerman s Temporary Intrinsics and Presentism [67]. Eternalism and presentism come in different kinds of formulations. They can be formulated concerning time itself or the occupants of time. I will not discuss here whether these formulations are equivalent since for our introductory purpose it suffices to sketch the big picture. In the time-formulation, Ted Sider, an eternalist, characterises presentism as the doctrine that only the present is real [60, p. 325]. Here he is talking about time itself, so according to Sider s presentist every non-present time is not real. The future is not yet real and the past not anymore, one might want to add. When formulated with the occupants in mind, the debate is about what there is or about the range of things to which we re ontologically committed [11, p. 211]. Sider writes: A presentist thinks that everything is present; more generally, that, necessarily, it is always true that everything is (then) present [60, p. 326]. Here the contrasting class does not consist of the other times (future and past times), but of the non-present objects. Dinosaurs do not belong to everything since

7 Florian Fischer: Introduction 5 they are not present, according to Sider s presentist. Phrasing it in slightly more formal terms, the everything suggests a general quantifier. Together with the mantra that to be is to be the value of a bound variable [56] [54] we can characterise presentism in the way Ned Markosian did: According to Presentism, if we were to make an accurate list of all the things that exist i. e. a list of all the things that our most unrestricted quantifiers range over there would be not a single non-present object on the list [36]. As some have argued that the presentist cannot even articulate her own view consistently 4, formulations matter a great deal here. Note that Sider speaks of real while Markosian uses exists. Asked whether Socrates exists, the presentist could give the (plausible) answer No, he existed. The presentist thus could acknowledge that Socrates is presently not existing. However this denial does not imply that Socrates is on a par with Santa according to the presentist. In contrast to Santa, Socrates, as far as we know, existed. Socates exists used to be true, while Santa exists was never true. The presentist thus neither has to bulldoze the difference between Socrates and Angela Merkel nor the difference between Socrates and Santa. In contrast to this, it sounds much more implausible to say that Socrates is not real, just because he is not present. We leave the matter be and turn to the presentist s antagonist eternalism. Eternalism states that there are such things as merely past and future 5 entities [60, p. 326]. You may have noticed that this is the occupants-formulation and that with there is we have an existential quantifier. Sider s formulation is quite careful. The merely excludes entities which are also present, entities with which the presentist (in Sider s fashion) would not have a problem. Furthermore, the existential quantifier is very modest: One (merely) past entity suffices to make there are such things as merely past and future entities true. Thus even at the last moment of time, where there are no future entities, Sider s formulation could still differentiate presentism from eternalism. Trenton Merricks supplies a time-formulation of eternalism: Eternalism says that all times are equally real. [42, p. 103]. The presentist could actually agree in wording to this, if not in spirit, of course. For the presentist the all will range over the present only. It is thus trivially true for her that all times are equally real, as there is only one time. The idea behind the time-formulation of eternalism is clear however. There are times other than the present and these are as real as the present. It is not the case that the future and the past subsist, while only the present exists. Even my earlier formulation that the eternalists believe that all of

8 6 KRITERION Journal of Philosophy, 2016, 30(2): 3 28 (space-)time exists on a par is not enough to define eternalism, since all of (space-)time could be unreal. Then it would be on a par but not in the way the eternalist wants. The formulation may suffice to distinguish presentism from eternalism, however. Merricks also offers a different characterisation of eternalism: Objects existing at past times and objects existing at future times are just as real as objects existing at the present. [42, p. 103]. This is the occupants formulation, obviously. Once again I would query that the presentist must not deny the reality of (merely which Merricks doesn t mention) past and future objects but maybe non-existing real entities seem strange. Let s fight squalidness with abundance and hear another characterisation of eternalism, this time from David Lewis: There is nothing so far away from us as not to be part of our world. Anything at any distance at all is to be included. Likewise the world is inclusive in time. No long-gone ancient Romans, no long-gone peterodactyls, no long-gone primordial clouds of plasma are too far in the past, nor are the dead dark stars too far in the future to be part of this same world. [32, p. 1] Lewis, admittedly rhetorically brilliant, quote nicely captures the egalitarian tendencies of the eternalist. All times are part of this same world and time is like space. The former we have heard before, while the latter offers a new aspect of eternalism. Eternalists often overemphasize that time is just one dimension of space-time and thus hold that time and space are alike, or at least that time is very much like the dimensions of space [36]. They believe that x is later then y is just another transitive, irreflexive, asymmetrical relation, like x is left of y. Eternalists would like to stand in thought outside the whole temporal process and describe the world from a point which has no temporal perspective at all, but surveys all temporal positions at a single glance. [... ] The different points of time have a relation of temporal precedence between themselves, but no temporal relation to the viewpoint of the description. [14, p. 369]. Dummett s quote hints at the fear of the eternalist that the presentist s ontological prioritisation of the present as the point of view of description deprives presentism of objectivity. Perhaps this fear is justified, perhaps not. 6 Of course we cannot end the (eternal?) battle of presentists and eternalists in this meagre introduction. Let us listen to some allegedly soothing tunes instead: These two ways of thinking, the way of time and

9 Florian Fischer: Introduction 7 history and the way of eternity and of timelessness, are both part of man s effort to comprehend the world in which he lives. Neither is comprehended in the other nor reducible to it. [49, p. 69]. This quote by Oppenheimer can be used to challenge the very foundation of the eternalist/presentist debate. Maybe they are not two mutually exclusive alternatives. Maybe they could even be combined: Hybrid views acknowledge that the world may be thought of as an existent four-dimensional entity, [... ] but retain the idea that there is something special about present times [10, p. 590] with this, Craig Callender hints at a possible combination of eternalsim and presentism. Another way to question the classical eternalism/presentism distinction is to say that it is not exhaustive. Presentists hold the present dear, while eternalists believe all of (space-)time to be ontologically homogeneous. What of the people who want to distinguish between the past and the future? You believe the past to be settled, while the future holds a variety of possible developments? Maybe then the growing block theory is something for you. According to its proponents only objects that are either past or present but not objects that are future exist. [36]. According to this theory, the past and present are on a par while the future is differentiated from them. The present just happens to be the edge of existence, i. e. the border of the block. And this block is growing, because the universe is always increasing in size, as more and more things are added on to the front end (temporally speaking) [36]. This growing of the block is supposed to be the reason why the present always differs in content. We can distinguish the question whether the present is ontologically special or not from the question whether what exists changes over time or not. Following Cord Friebe s [23, p. 43] terminology, we call a view according to which existence is time relative dynamic and one where this is not the case static. Classic eternalism is static, as neither the present is distinguished nor what there is changes over time. On the other end of the spectrum we have classic presentism where the present is so special that all there is, is present. One might think that presentism is the only dynamic theory but the recently mentioned growing block is dynamic as well, at least according to Friebe [23, p. 44]. A static theory besides classical eternalism is the so-called moving spotlight theory. According to the moving spotlight theory, the present is like a spotlight (hence the name) which sheds its light on the present point in time. It moves (yes!) alongside the time line, thus always rendering a different time present. You may be wondering now with which speed the present moves,

10 8 KRITERION Journal of Philosophy, 2016, 30(2): 3 28 or how it moves at all, if the time line is supposed to be time. Well, of course the spotlight-present moves in meta-time. If you find meta-time suspicious and suspect that movement in meta-time needs meta-metatime to be explicated, then you are in the midst of McTaggart s argument [37]: Tense realism is the tenet that tensed determinations, such as being past, present, or future, are among the ingredients of temporal reality. Famously, McTaggart maintained that the reality of time implies tense realism, but argued that tense realism is incoherent [66, p. 281]. The literature on McTaggart s alleged [34] proof of the unreality of time is legion, and we can t go into it here, but note that his contradiction charge is alive and kicking. These problems of a relatively moving present hint at why the presentist cannot take the whole of (space-)time as ontologically prior and then distinguish the present: this would lead right into the contradictory arms of McTaggart! The presentist must think of the present as ontologically prior and of the (space-)time as derivative (Cf. [22]). This does not imply a denial of the reality of the non-present parts of (space-)time, like the presentist must not deny the reality of dinosaurs. Be that as it may, we now have to go on and turn to the question of persistence. 2 Endurance/Perdurance The endurance/perdurance debate is about the persistence of objects through (space-)time. 7 It revolves around the so-called problem of identity through time [32, p. 202]: There is an imminent contradiction with Leibniz Law for changing objects. To see this, we must first get a grip on the concept change. A theory of change is necessarily concerned with the persistence of objects or systems through time and thus a criterion for change is that something persists through the change. It is a different situation whether a red ball is replaced with a blue one, or whether a red ball turns blue. So, one benchmark for a theory of change is to distinguish change from exchange. 8 Call this continuity. 9 A second benchmark for a theory of change is which sounds almost trivial that there needs to be a change. I call this, neutrally, difference as it may consist in a something else. For example, for Kant a persisting substance changes by exchanging ( Wechsel ) its properties, meaning that the change of one entity can consist in the ceasing and beginning of other entities [29, A187 B231]. However, there is more to difference : The properties which are exchanged must also be incompatible in order for

11 Florian Fischer: Introduction 9 there be change. If something is first red and then square, it does not amount to change. 10 As we have sketched out, change needs identity as well as difference [41, p. 89]. On the face of it, incompatible properties account for the difference, while the continuity is ensured by the (numerical) identity of the persisting object, but here the problem of persistence has its systematic roots. According to Leibniz Law of indiscernibility of identicals 11, things which are identical have the same properties: x y[x = y F (F x F y)]. This is in tension with the very idea of change, according to which one and the same persisting object is supposed to have different, even incompatible, properties. 2.1 The problem of persistence During the rise of the new analytical metaphysics the question of the nature of change was formulated anew by David Lewis. The possible solutions to the problem of change he discusses are, till today, the base for the accounts of persistence. These modern accounts fall into two camps, which have their own ways of dealing with the imminent contradiction with Leibniz Law. 12 Let us say that something persists iff, somehow or other, it exists at various times; this is the neutral word. Something perdures iff it persists by having different temporal parts, or stages, at different times, though no one part of it is wholly present at more than one time; whereas it endures iff it persists by being wholly present at more than one time [32, p. 202] Figure 1: Endurantism Figure 2: Perdurantism

12 10 KRITERION Journal of Philosophy, 2016, 30(2): 3 28 Perdurantism: One possible solution is perdurantism, which describes objects as extended in time. Perduring objects do not only have spatial extension, but also temporal extension. The things we interact with in our everyday life are, according to perdurantism, threedimensional parts of actually four-dimensional objects. This is a dissolution of the contradiction, as the properties are instantiated by different temporal parts. A ball which is first red and then blue thus changes by having a red and a blue temporal part. The red temporal part is not identical to the blue temporal part and hence the incompatible properties can be instantiated without contradiction. This alleged solution of the problem of change comes with the price that, contrary to our intuitions, objects are four-dimensional space-time entities. We perdure; we are made up of temporal parts, and our temporary intrinsics are properties of these parts, wherein they differ one from another. There is no problem at all about how different things can differ in their intrinsic properties. [32, p. 204]. What constitutes continuity for the perdurantist? If there are just different objects instantiating different properties, how can the perdurantist distinguish change from exchange? The obvious answer is that the objects in question are temporal parts. Thus, there is a whole of which they are part, so that the continuity is supplied by the parthood relation. Ted Sider endorses a variant of perdurantism called the stage view, which identifies continuants with the stages themselves [61, p. 84] and not the four-dimensional whole. Here the three dimensional entities, located at their respective moments of time, are called stages and not temporal parts, precisely because they are not parts of a four-dimensional whole. Strictly speaking, the stages [... ] are only momentary entities but they are nevertheless said to persist through time by having counterparts at other times [4, p. 91]. In contrast to enduring objects the stages are not multi-located. Identity cannot be the continuity-maker, since the counterpart of something [... ] is never identical with the thing itself [30, p. 45]. The stages do not persist themselves, as they are confided to their respective temporal location but the stage view is nevertheless an account of persistence, since the counterpart relation establishes continuity. 13 One could launch a version of the famous Humphrey objection 14 against Perdurantism Counterpart : If the continuants of our everyday ontology [61, p. 84] are stages and these only have the temporal properties of their respective points in time, then it is hard to see how I can have any non-present properties. Sider answers to this with a variant of Lewis reply to the original Humphrey objection: I do have various tensed

13 Florian Fischer: Introduction 11 properties, such as the property of futurely being not straight. But this is no more a lack of straightness than is being possibly not straight [61, p. 85]. Notably, David Lewis, who holds a counterpart theory for cross-world identification, does not posit a counterpart relation between the threedimensional one-time located perdurantistic property bearers. Without arguments, however, it would be ad hominem to ignore it as a possible unifier. Lewis states: Perdurance, which I favour for the temporal case, is closer to the counterpart theory which I favour for the modal case. [32, p. 203] - and, sure, perdurance is closer than endurance, but counterparts would be even closer. Lewis gives us a hint of why he rejects counterpart-perdurantism: counterpart theory concentrates on the parts and ignores the [... ] individual composed of them. [32, p. 203]. Thus it is questionable whether the inner-world-counterpart account in spirit really is a perdurantistic solution or if it should better be pigeon-holed as an endurantistic account. Let s have a closer look at endurantism, then. Endurantism: Endurantism respects the every day intuition that objects are three-dimensional entities. Thus, enduring objects are multilocated, as they are located at every time of their existence. The endurantist takes the, allegedly, more intuitive route of three-dimensional objects, therefore the solution of the perdurantist is not possible for him. Perdurantism can be understood as time-indexing the object. Parallel to this the alleged solution of the endurantist can be depicted as temporally indexing the predicates. Call this view indexicalism. Object o being F at t 1 is reinterpreted by the indexicalist as o is F t1 or F t1 (o). This is not satisfactory, because an object which remains red would always instantiate different properties (red t1, red t2, red t3,... ). In light of this criticism adverbialism was invented. Here the copula is is amended with a temporal index, or a temporal adverb (hence the name adverbialism) is added to the sentence. So either The ball is t1 red or The ball is t 1 -ly red. In the debate the name adverbialism is used for both versions, but sometimes the temporal-adverb-variant is taken to be the stronger one. Without taking a stance on this, I will name the indexed-copula-variant copularism. It may turn out that metaphysically there is no difference between the two or that copularism is a subspecies of adverbialism; still, it helps to have the conceptual resources to distinguish them. Lewis depicts endurantism differently: Contrary to the surface appearance, intrinsic properties, like shapes are not really properties. They are disguised relations [32, p. 204]. Object o stands, say, in the F-relation to time t 1 and in the G-relation to time t 2. I call this variant relationalism

14 12 KRITERION Journal of Philosophy, 2016, 30(2): 3 28 and add it to our lists of solution candidates for the problem of change. An additional alleged solution in fact one that Lewis discusses in [32, p. 203] is presentism. Presentism is in so much a solution, as there is ever only one moment of time (i. e. the present) and thus never are any incompatible properties instantiated. As Presentism is not on a par with the other options it s an account about the nature of time and not the persistence through time it is hard to depict it in the same fashion as the other alleged solutions. 15 One way to presentists represent change is with temporal operators: when the object o is G G(o) it was the case that it was F: P F(o) 16, because [w]hile the eternalist can give the truth conditions [... ] in terms of quantification over past objects [... ] the presentist has to resort to irreducible tensed operators, which she does not take to commit her to the existence of past objects [65, p. 2062]. According to Lewis, however, presentism rejects endurance; because it rejects persistence altogether [32, p. 203]. Lewis thinks that for a presentist other times are on a par with fictions and that she thus does not give an account of persistence. But, at least according to her own claim, the presentist can distinguish between dinosaurs and unicorns. Only the former have been present, while the latter sadly will never have been present. True, [o]pponents of presentism have often argued that the presentist has difficulty in accounting for what makes (presently) true past-tensed propositions [... ] true in a way that is compatible with her metaphysical view of time and reality [65, p. 2047]. So, I merely want to note that Lewis argument is a non sequitur: From the presentists denial that the present is on a par with other times, it just doesn t follow that other times are on a par with fictions. A further possibility is to take the relation of property exemplification (E) as dependent on time: E t1 (o, f). This solution takes shapes to be (index-free) properties and accepts the existence of points in time besides the present just like Lewis own solution. It is in no need, however, of temporal parts. It goes back to a proposal by Uwe Meixner [39, p. 95]. Actually Meixner presents a slightly different version with a three-place relation of property exemplification E 3 which relates an object, a time and a property: E 3 (o, t 1, f). I call this proposals in honour of their as far as I know inventor Meixnerism Etn and Meixnerism E 3. For both versions the relation can either be one of second order logic, if its relatum is a property (like F or G ) or it can also be formalized in first order logic taking the corresponding singular terminus ( redness corrseponding to the property of being red so, f or g ). I take no sides here. Maybe the choice is between logical simplicity and metaphysical

15 Florian Fischer: Introduction 13 dubiousness, maybe it doesn t matter. Note that Meixner himself takes f as a proper name for an universal. Let us sum up: Name Account Continuity Perdurantism F(o t1 ) G(o t2 ) Parthood Perdurantism Counterpart F(s t1 ) G(s t2 ) Counterpart Indexicalism F t1 (o) G t2 (o) Multi location Copularism O is t1 F and O is t2 G Multi location Adverbialism O is t 1 -ly F and O is t 2 -ly G Multi location Relationism F(o, t 1 ) G(o, t 2 ) Multi location Presentism PF(o) G(o) Identity Meixnerism Etn E t1 (o, f) E t2 (o, g) Identity Meixnerism E 3 E 3 (o, t 1, f) E 3 (o, t 2, g) Identity 3 Tense/Tenseless Now we turn to the controversy about the status of tense. 17 This debate started out within the philosophy of language. The old B-theoreticians contested the relevance of the reference to the present moment. They thought linguistic phenomena like tense and aspect and words like now or tomorrow belong only to the surface structure of sentences and in fashioning canonical notations it is usual to drop tense distinctions. [57, p. 170]. The idea is that our messy language obstructs the access to its own semantical or logical structure and deviation from the surface structure helps to clear things up. Thus, the core of the old B-theory is the enterprise of paraphrasing statements so as to isolate their logical structures [55, p. 44]. 3.1 The old B-theory and the belief in unrestricted translatability Eternalism denies an objective reference to the present moment and thus tensed sentences must have tenseless truth conditions. According to the eternalist the surface structure of a tensed sentence does not correspond to an objective feature in the world. The simple correspondence theory of truth states that a sentence like Paris is the capital of France is true just in case the corresponding state of affairs holds true, i. e. Paris really is the capital of France. Likewise It is raining now should be true just in case it is raining now. 18 An objective reference to the present moment (now) leads to an objective truth value. As the eternalist drops this objective reference to the present moment, she must come up with

16 14 KRITERION Journal of Philosophy, 2016, 30(2): 3 28 an ersatz truth-maker, otherwise he would have to deny that tensed sentences have a truth value at all. The old B-theoreticians 19 believed in translatability: All tensed sentences are translatable without a loss of meaning into tenseless sentences. There were different accounts on the market of how this translation should look like in detail. Gottlob Frege [21, p. 297] voted for a date indication analysis: a tensed sentence like (S 1 ) It is raining now actually means something along the lines of it is raining at Thursday the 13th May Bertrand Russell s token-reflexive analysis [58, p. 108] in contrast states that the sentence should be translated into It is raining at the point in time that is co-temporal with this utterance. 3.2 Prior and Perry on now Arthur Prior has famously argued for the irreducibility of tense. Tensed sentences and beliefs are not translatable into tenseless ones, according to Prior. However, they are important for our actions. In [53] Prior s example is the joy we feel after an important test is over. Sentences we utter at such occasion cannot be understood tenselessly and only tensed beliefs explain our actions and change of emotions (i. e. from stressed to relieved). One says, e.g. Thank goodness that s over!, and not only is this, when said, quite clear without any date appended, but it says something which it is impossible that any use of a tenseless copula with a date should convey. [53, p. 17]. Prior was very explicit about the non-translatability of tensed sentences and claimed that the attempt of the old B-theoreticians to substitute indexicals like now with a date and time indication failed. What causes our joy after the important test is not that the test is over at, say, 4 pm. We would have known that before hand. Also the tenseless relation of earlier/later does not help in this case. It is tenslessly true that 4.15 pm is later than 4 pm (on the same day). Neither the tenseless fact that the test lasts till 4 pm, nor the tenseless fact that 4.15 pm is later than 4 pm explains our joy and even both together are not sufficient. It is the fact that it is 4.15 pm now that gives meaning to the sentence Thank goodness that s over! and that explains our feelings of joy and our actions (celebrating). Thank goodness that s over! has an implicit reference to the present moment and stands for Thank goodness that s over now! :

17 Florian Fischer: Introduction 15 It certainly doesn t mean the same as, e. g. Thank goodness the date of the conclusion of that thing is Friday, June 15, I954, even if it be said then. (Nor, for that matter, does it mean Thank goodness the conclusion of that thing is contemporaneous with this utterance. Why should anyone thank goodness for that?). [53, p. 17] Neither the translation strategy of the old B-theory nor the token reflexive strategy were able to capture the meaning of the tensed sentence Thank goodness that s over! according to Prior. Prior was chiefly concerned with matters of time and thus his paper focused on the indexical now, which is also our topic here. John Perry made a more general claim concerning indexicals. Perry s 1979 paper [50] featured three examples of which I would like to introduce the one starring the tardy professor: [A] professor, who desires to attend the department meeting on time, and believes correctly that it begins at noon, sits motionless in his office at that time. Suddenly he begins to move. What explains his action? A change in belief. He believed all along that the department meeting starts at noon; he came to believe, as he would have put it, that it starts now. [50, p. 4] Perry called beliefs which contain indexicals like I, here and now locating beliefs. Locating beliefs are necessary for actions, since the corresponding tenseless beliefs do not explain the sudden movement of the tardy professor. Perry s conclusion was that we believe the same thing, but in different ways: As time passes, I go from the state corresponding to The meeting will begin to the one corresponding to The meeting is beginning and finally to The meeting has begun. All along I believe of noon that it is when the meeting begins. But I believe it in different ways. And to these different ways of believing the same thing, different actions are appropriate: preparation, movement, apology. [50, p. 19] Since we are not concerned with beliefs here the details of Perry s account do not matter. We can, however, state that Perry puts forward a strong argument against the translatability of tensed sentences into tenseless ones. After Prior and Perry it has generally been accepted that tensed sentences and beliefs are necessary for our actions and that they cannot be translated without a loss of meaning into tenseless ones.

18 16 KRITERION Journal of Philosophy, 2016, 30(2): The New Tenseless Theory of Time The New Tenseless Theory of Time (NTT) differs from the old B-theories by acknowledging the irreducibility of tensed sentences. So even B- theories accept that there are sentences whose truth values depend on time. The NTT thus incorporates more dynamics, as one would expect. But still the NTT is an eternalistic theory, i. e. every point in time is ontologically on a par and there is no objective reference to the present moment. So, how does a non-tensed world view go alongside with irreducible tensed sentences? The NTT exploits the fact that the surface structure of a sentence can deviate from the structure of the truth-maker of this sentence. 20 According to the old B-theory, tensed sentences could, or even should, be translated into tenseless ones, but after Prior and Perry this thesis must be dropped. [R]ecent defenders of the tenseless view have come to embrace the thesis that tensed sentences cannot be translated by tenseless ones without loss of meaning. [48, p. 58]. The new B-theoreticians still call their view tenseless, but this tenselessness now concerns the structure of the world. 21 With the NTT the link between metaphysics and language became much tighter. One can only truly be called a B-theoretician nowadays if one holds a tenseless world view. 22 Tensed discourse is indeed necessary for timely action, but tensed facts are not [48, p. 58]. Tensed beliefs can vary in their truth value but tenseless ones do not change their truth value. 23 Tenseless truth conditions can be given for every tensed belief, according to the NTT. Tensed sentences may have different truth values and thus must have different truth conditions. This is at odds with the plausible claim that any sentence, and thus also a tensed sentence, has the same meaning in every context. The champion of the NTT, David Hugh Mellor himself, agrees that truth conditions must surely supervene on meanings [41, p. 6]. A sentence like it is raining now has the same meaning always and everywhere. But it seems that according to the NTT the sentence must change its truth conditions, since it must be made true by different tenseless facts at every time. Only a tensed theoretician can maintain that it is raining now has the same tensed truth conditions in every context, namely that it is true if the tensed fact that it is raining now occurs. At first glance it seemed that the B-theoretician could just posit a different reduction strategy to acknowledge Prior s and Perry s arguments. Instead of translating the tensed sentence she claims that there are

19 Florian Fischer: Introduction 17 different tenseless truth conditions for every token of the sentence. As we have seen, however, this contradicts the claim that a sentence has the same meaning at every time and that truth conditions supervene on meaning. Mellor s NTT from Real Time II is supposed to solve this problem. Mellor claims that a token of a tensed sentence is tenselessly true and has only one truth condition. This acknowledges the variability of the truth value on the type level. If a token of a tensed sentence is true, then it is a-temporally true, made true by a tenseless fact. With this distinction between type and token in place, Mellor can account for the stable meaning of a tensed sentence. In his first attempt, Real Time [40], Mellor understood the meaning of a tensed sentence as a function from utterances to truth conditions. Due to strong critique [48] he changed his position and in Real Time II [41] he understands the meaning of a tensed sentence as a function from B-times to B-truth conditions [41, p. 59]. Meaning is concerned with sentence types, according to Mellor. Tenseless sentences have constant functions as their meaning, while the functions of tensed sentences can be non-constant. The possibility of variation in the truth conditions (the co-domain of the function) allows for the variability in the truth value Packages We have introduced the dynamic/static distinction in the context of the presentism/eternalism debate (sec. 1). A quick reminder: a view is dynamic iff existence is time relative, otherwise static. In section 3 we have introduced the distinction between A- and B-theory. 25 Combining both leads to four time-reality combinations: time reality 1. B-theory static 2. B-theory dynamic 3. A-theory static 4. A-theory dynamic Classical eternalism is a static B-theory and classical presentism is a dynamic A-theory. The moving spotlight theory states that existence is not time relative, but the present is nevertheless ontologically distinguished and thus it s a static A-theory, while the growing block theory is at least allegedly a dynamic B-theory. Presentists are virtually always endurantists. Many may even think

20 18 KRITERION Journal of Philosophy, 2016, 30(2): 3 28 that presentism and perdurantism are inconsistent. At least Sider holds that no contemporary philosopher defends the combination of presentism and perdurance. [59, p. 68]. Contrary to that, Berit Brogaard does not only think that presentism and perdurantism are compatible, but develops a Presentist Four-Dimensionalism in [7]. Jorgen Hansen builds his Stage View Presentism on this which he claims to be an appealing alternative for presentists who remain impartial to both the endurantist and the worm theories of persistence [26]. In the debate about persistence, eternalism is (often) presupposed. This hints at a prima facie compatibility of both endurantism and perdurantism with eternalism. This is plausible. Given eternalism the disagreement is about what the world-line represents: perdurantist think this is the whole object, whereas endurantists believe the world-line to represent the history of the object. Figure 1 shows the object O e multilocated, while in figure 2 the object O p is the whole world-line and at each point in space-time there is only a part (like TP 1, TP 2,... ). So, perdurantism seems to come pack and parcel with eternalism: It is certainly true that most if not all four-dimensionalists presuppose eternalism. [59, p. 71]. The endurantist is, at least prima facie, free to choose, however. The combination of eternalism and perdurantism is called manifold theory [59, p. 69]. The deal might be even more inclusive for the perdurantist, as it may include the tenseless theory (see section 3.3). The other way around is quite inclusive as well: Reductionists about tense, then, are invariably eternalists. [59, p. 14]. So, If you are a detenser, you almost have to be an eternalist. Most probably you are then also a perdurantist, but this is not necessary: You may be a de-tensing, eternalistic endurantist for whatever reason. Arthur Prior compiled the other one-click-bundle available on the market: He advocates the combination of tensed theory, endurantism and presentism. Besides arguing for presentism [59, p. 18], Prior states: it is not the case that one part of me was a boy in New Zealand while another part of me is a man in England; it is I who was that boy, and I - the same I - who am the man [51, p.183] - hence endurantism. He further believes that It is raining actually means It is raining now [46, p. 23]. There seems to be a tendency here: On the one hand, the perdurantism/tenseless theory/eternalism package fits well and is often bought in one. Endurantism, tensed theory, and presentism, on the other hand, are not so tightly interwoven. The mentioned packages offer only a glimpse

21 Florian Fischer: Introduction 19 at the various links between the debates. So, even if the three debates about the nature of time, the persistence through time, and the reference to the present moment start out independently, a satisfactory account in the philosophy of time may very well need to take all three fields 26 and their prerequisites into consideration. 27 Acknowledgements I would like to thank the audience at the 2016 Time and Change workshop in Bonn, where I presented the persistence part of this introduction, for a useful and at the same time pleasant discussion. The way I see the philosophy of time which might be in some areas non-standard; hence A slightly opinionated introduction has developed over the last couple of years. I cannot list all the people with which I had talked about the topic during this period, but you know who you are (you are all selfidentical). I would like to thank the members of the SPoT (at least those, with which I am not self-identical) for the incredible time. Especially I want to thank Dan Deasy, Sonja Deppe, Jesse Mulder, Thorben Petersen, Alastair Wilson and Pamela Zinn who have read this text and helped to improve it a great deal. Notes 1 Objects endure, if they persist by being wholly present. Thus to say that Socrates persists is just to say that the whole of him is present at each times of existence. [8, p. 883]. Numerically one object can be completely present at t 1 and t 2. When it is present at t 1, however, it can neither be present at t 2 nor can a part of it be present at t 2. The worldline of an enduring object represents its history through space and time (or space-time). This suffices as a rough characterization but it is quite controversial how to capture wholly present exactly. [W]hat is it for something to be wholly present at a time? It s surprisingly difficult to say [12, p. 318]. 2 Kit Fine distinguishes between ontic and factive presentism: Ontic presentism is an ontological position; it is a view about what there is. Factive presentism, on the other hand, is a metaphysical rather than an ontological position; it is view about how things are, quite apart from what there is [16, p. 299]. Ontic presentism can be associated with what I will call the occupants-formulation of presentism. The, in my terminology, time-formulation does not correspond to Fine s factive presentism, however. The time-formulation and the occupants-formulation may turn out to be equivalent, while Fine argues for a substantial difference between factive and ontic presentism, as, for example, [i]t is readily possible for a factive presentist not to be an ontic presentist [16, p. 299]. Fine s factive presentism is compatible with ontic eternalism, as, as Giuliano Torrengo puts it, the presentist here is exploiting the metaphysical view of the A-theory of time to solve the

22 20 KRITERION Journal of Philosophy, 2016, 30(2): 3 28 contradiction, rather than her ontology restricted to presently existing entities [64, p. 255]. 3 It is important to speak of space-time rather then only time, as it is sometimes argued that modern physical theories, especially the SRT and ART, supply a posteriori arguments for the philosophy of time. See the contribution of Cord Friebe [22] in this volume, for an argument completely contrary of what is otherwise assumed that only presentism can cope with the peculiarities of the ART, namely the closed timelike curves of, so-called, Gödel universes. 4 Presentism, it is argued, is either trivial or clearly false (Cf. [44, p ]). The exists in the presentist s claim that only what is present exists, must be understood either tensed or tenseless, according to the critics. It is trivially true that only present entities exist now, while it is clearly false that only present things exist simpliciter (just think about Socrates). Harold Noonan answers to this charge: Likewise, I suggest, it is neither trivially true nor obviously false that everything (simpliciter) which is temporally locatable is presently existent. [47]. 5 Perhaps it is even too much of a concession towards presentism to speak of past and future entities. Future and past only make sense in reference to the present. Maybe the hardcore eternalist should say that all times/entities are ontologically on a par. He should stick with the tenseless relations of earlier and later and completely shun talk of present, future and past. 6 See [22] in this volume for a discussion of objectivity of presentism in the ART. 7 Also here talk of space-time instead of time might be important, as it is sometimes argued that perdurantism has an advantage over endurantism regarding compatibility with the SRT (e. g. [2] and [3]). There Yuri Balashov argues that the endurantist, and only she, is committed to claims containing tensed determinations, which are allegedly incompatible with the SRT. See my [20] for the attempt of a rebuttal of Balashov s originally asymmetry thesis. 8 Arguably already Aristotle has distinguished change form exchange, as he clearly distinguishes change from the processes of coming to be and passing away, according to Thomas Buchheim [9, p. XVII]. Coming to be and passing away are not just changes of some always existing entity 9 I have chosen the term continuity in order to not pre-decide the debate. The alleged unifier might be identity or parthood or multilocation or something else. 10 Change needs at least continuity and difference. See [19] for a longer introduction of alleged characteristics of change. There I list: difference, identity, incompatibility, irreversibility and succession. 11 Identity looms large in Leibniz s philosophy. He is responsible for articulating two principles that, he claims, are constitutive of identity. The first, more controversial, of these, called the identity of indiscernibles, says that qualitative indiscernibility implies identity. The second, often referred to as Leibniz s Law or the Indiscernibility of Identicals, says that identity implies qualitative indiscernibility. According to Leibniz s Law, if a is identical with b, every quality of a will be a quality of b. [24]. 12 The contenders of the modern debate seem to be content with a removal of the logical contradiction with Leibniz law. This, however, is not a solution of the problem of change, but merely a precondition: Every theory which doesn t address the lurking contradiction is a non-starter. (As argued in [18].)

23 Florian Fischer: Introduction Uwe Meixner [38] also presents a view which he does not endorse with a temporal counterpart relation, called supereternalism. Meixner claims that with it one can have change, although no object whatever changes in the sense that it ever has any other properties appropriate for change than those it has now. [38, p. 432]. Both views seem quite similar to me. 14 For David Lewis your counterparts are not really you. For each of them is in his own world, and only you are here in the actual world. Indeed we might say, speaking casually, that your counterparts are you in other worlds that they and you are the same; but this sameness is no more a literal identity than the sameness between you today and you tomorrow. It would be better to say that your counterparts are men you would have been, had the world been otherwise [31, p ]. Kripke finds this absurd and has launched his, now famous, Humphrey objection against it: Thus, if we say Humphrey might have won the election (if only he had done such-and-such), we are not talking about something that might have happened to Humphrey but to someone else, a counterpart. Probably, however, Humphrey could not care less whether someone else, no matter how much resembling him, would have been victorious in another possible world [30, p. 45]. 15 See the contribution of Jesse Mulder [45] in this volume, for an attempt of Defining Original Presentism. There Mulder agrees with Jonathan Tallard [62], that eternalism and presentism need to be differentiated on a much more fundamental level, then usually attempted. 16 See e. g. [25, p. 50] for an introduction to temporal logic. See [46] for a detailed reconstruction and further development of Prior s tense logic. 17 There are several related debates. Giuliano Torrengo offers the following, helpful, classification: The distinction between A-theory and B-theory is metaphysical. According to the A-theory, the passage of time is real, and, thus, tense determinations (such as being present, past, and future) are genuine features of reality. According to the B-theory tense determinations are reducible to relations between a perceiver and a position in time. The distinction between the presentist and the eternalist is ontological. According to the presentist, in our most unrestricted domain of quantification we find only presently existing entities, whereas according to the eternalist also past and future entities exist. The distinction between the serious tenser and the de-tenser is semantic. According to the serious tenser tensed sentences express tensed propositions, namely propositions that are temporally undetermined (their truth-value being possibly variable through time), whereas according to the de-tenser tensed sentences express tenseless propositions, namely propositions that are temporally determined (bearing a determined truth-value regardless of time) [64, p. 253]. However, the terminology is far from homogeneous in this area of philosophy. So, in this introduction I will switch freely between the terms tensed theory, tensers, and A-theory (as well as their counterparts) if no a specific linguistic or ontological reading is necessary. Otherwise I make this explicit. 18 [28] provides an overview of the semantics of the word now in ordinary language and discusses formal systems, drawing heavily on the work of Arthur Prior [52]. 19 Following McTaggart (1908), tensed and tenseless temporal judgments are often called A-judgments and B-judgments, respectively. The concepts now, was, will, and the like are called A-concepts, whereas the concepts before, after, and related concepts are called B-concepts [59, p. 12].

24 22 KRITERION Journal of Philosophy, 2016, 30(2): We can have, for example, definite truth values for disjunctive sentences, without positing disjunctive facts in the world. 21 Sonja Deppe [13], however, questions the claim of the tenseless theorists that the relational structure of earlier/later is a metaphysical feature of time itself. With the help of Henry Bergson a philosopher who is, sadly and wrongly, underrepresented in the contemporary debate she tries to show that this relational structure is part of our intellectual engagement with temporal phenomena instead. 22 See my paper [17] in this volume. There I argue that the NTT may be too metaphysical for some philosophers. Arguably Rudolf Carnap belongs in the camp of the old B-theory, but cannot make the transition to the NTT, because this contradicts his inter-translatability thesis and metaphysical neutrality thesis. 23 It is sometimes stated that tenseless sentences are always true if they are sometimes true, but this is only one half of the story. There are two ways to negate the variation in truth value. A sentence can either always have a truth value (omnitemporal) or not in a timely sense at all (a-temporal). 5 is a prime number is an example for an a-temporal truth [23, p. 60]. This sentence is a-temporal because it is meaningless to ask When is 5 a prime number?. A-temporal sentences do not vary in their truth value because conceptually they simply cannot. Omni-temporal sentences could vary, because they are located in time but, for some reason or other, just do not. 24 One possible critique is that this approach might not work if nature is too complex. If time and space are continua, as for example Aristotle [1, ch. 5] has famously argued, then there are at least uncountably many items in the domain of the function. I don t want to claim, however, that this attack is successful or promising, I m merely mentioning it. 25 See [45, p. 14] in this volume for a more Fine -grained characterisation, where Jesse Mulder, following Kit Fine, distinguishes three versions of A-theory. 26 Of course, there might be even more debates which have to be taken into account, as the epistemology of time or the history of philosophy. See the contribution of Pamela Zinn [68] in this volume, which analyses Lucretius account of time in his De rerum natura, focusing precisely not only on the nature of time but also on its perception. 27 If you disagree with something, dear reader, then I m satisfied. I would be glad if you could prove me wrong and present your work on one of our SPoT-meetings: - please feel welcome to! Florian Fischer University of Bonn Institut für Philosophie Am Hof Bonn <fischerf@uni-bonn.de> <

25 Florian Fischer: Introduction 23 References [1] Aristoteles. Physik. Ed. by H. G. Zekl. Vol. V-VIII. Hamburg: Meiner, [2] Yuri Balashov. Enduring and Perduring Objects in Minkowski Space-Time. In: Philosophical Studies 99 (2000), pp [3] Yuri Balashov. Special Relativity, Coexistence and Temporal Parts: A Reply to Gilmore. In: Philosophical Studies 125 (2005), pp [4] Jiri Benovsky. Persistence Through Time and Across Possible Worlds. Ontos Verlag, [5] John Bigelow. Presentism and Properties. In: Philosophical Perspectives 10.Metaphysics (1996), pp [6] Andrea Bottani, Massimiliano Carrara, and Daniele Giaretta. Individuals, Essence, and Identity. Themes of Analytic Metaphysics. Kluwer, [7] Berit Brogaard. Presentist Four-Dimensionalism. In: The Monist 83.3 (2000), pp [8] Jeffrey E. Brower. Aristotelian Endurantism: A New Solution to the Problem of Temporary Intrinsics. In: Mind (2010), pp [9] Thomas Buchheim, ed. Über Werden und Vergehen - De generatione er corruptione. Hamburg: Meiner, [10] Craig Callender. Shedding Light on Time. In: Philosophy of Science 67.3 (2000), p [11] Thomas M. Crisp. Presentism. In: The Oxford Handbook of Metaphysics. Ed. by Michael J. Loux and Dean W. Zimmerman. Oxford University Press, [12] Thomas M. Crisp and Donald P. Smith. Wholly Present Defined. In: Philosophy and Phenomenological Research 71.2 (2005), pp [13] Sonja Deppe. The Mind-Dependence of the Relational Structure of Time (or: What Henri Bergson Would Say to B-theorists). In: New Developments in Philosophy of Time. Ed. by Florian Fischer. Kriterion Journal of Philosophy, 2016.

26 24 KRITERION Journal of Philosophy, 2016, 30(2): 3 28 [14] Michael A. E. Dummett. The Reality of the Past. In: Truth and Other Enigmas. Harvard University Press, [15] Michael A. E. Dummett. Truth and Other Enigmas. Harvard University Press, [16] Kit Fine. Tense and Reality. In: Modality and Tense. Oxford: Oxford University Press, [17] Florian Fischer. Carnap s Logic of Science and Reference to the Present Moment. In: New Developments in Philosophy of Time. Ed. by Florian Fischer. Kriterion Journal of Philosophy, [18] Florian Fischer. Das Problem der Persistenz. In: Proceedings of XXII. Kongress der Deutschen Gesellschaft für Philosophie [19] Florian Fischer. Limit Deciding Dispositions. In: Vivarium ((forthcoming)). [20] Florian Fischer. On the Asymmetry of Endurantistic and Perdurantistic Coexistence in Special Relativity. In: Philosophia Naturalis 49.1 (2012), pp [21] Gottlob Frege. The Thought: A Logical Inquiry. In: Mind (1956). Ed. by Peter Geach, pp [22] Cord Friebe. Time Order, Time Direction, and the Presentist s View on Spacetime. In: New Developments in Philosophy of Time. Ed. by Florian Fischer. Kriterion Journal of Philosophy, [23] Cord Friebe. Zeit Wirklichkeit Persistenz. Eine präsentistische Deutung der Raumzeit. Paderborn: Mentis, [24] Andre Gallois. Identity Over Time. In: The Stanford Encyclopedia of Philosophy. Ed. by Edward N. Zalta. Winter [25] James W. Garson. Modal Logic for Philosophers. Cambridge University Press, [26] Jorgen Hansen. A Case for Stage View Presentism. [27] Aleksandar Jokic and Quentin Smith, eds. Time, Tense, and Reference. A Bradford Book, [28] Hans Kamp. Formal Properties of Now. In: Theoria 37.3 (1971), pp [29] Immanuel Kant. Critique of Pure Reason. Ed. by P. Guyer and A. Wood. The Cambridge Edition of the Works of Immanuel Kant. Cambridge: Cambridge University Press, 1998.

27 Florian Fischer: Introduction 25 [30] Saul A. Kripke. Naming and Necessity. Harvard University Press, [31] David K. Lewis. Counterpart Theory and Quantified Modal Logic. In: Journal of Philosophy 65.5 (1968), pp [32] David K. Lewis. On the Plurality of Worlds. Blackwell Publishers, [33] Michael J. Loux and Dean W. Zimmerman. The Oxford Handbook of Metaphysics. Oxford University Press, [34] E. J. Lowe. McTaggart s Paradox Revisited. In: Mind (1992), pp [35] Ned Markosian. A Defence of Presentism. In: Oxford Studies in Metaphysics 1.3 (2004), pp [36] Ned Markosian. Time. In: The Stanford Encyclopedia of Philosophy. Ed. by Edward N. Zalta. Spring [37] J. Ellis McTaggart. The Unreality of Time. In: Mind (1908), pp [38] Uwe Meixner. Change and Change-Ersatz. In: Individuals, Essence, and Identity. Themes of Analytic Metaphysics. Ed. by Andrea Bottani, Massimiliano Carrara, and Daniele Giaretta. Kluwer, [39] Uwe Meixner. David Lewis. nachgedacht. Paderborn: Mentis, [40] David Hugh Mellor. Real Time. Cambridge: Cambridge University Press, [41] David Hugh Mellor. Real Time II. London: Routledge, [42] Trenton Merricks. Goodby Growing Block. In: Oxford Studies in Metaphysics 2 (2006). [43] Trenton Merricks. Persistence, Parts, and Presentism. In: Noûs 33.3 (1999), pp [44] Ulrich Meyer. The Presentist s Dilemma. In: Philosophical Studies (2005), pp [45] Jesse M. Mulder. Defining Original Presentism. In: New Developments in Philosophy of Time. Ed. by Florian Fischer. Kriterion Journal of Philosophy, [46] Thomas Müller. Arthur Priors Zeitlogik: Eine problemorientierte Darstellung. Paderborn: Mentis, 2002.

28 26 KRITERION Journal of Philosophy, 2016, 30(2): 3 28 [47] Harold Noonan. Presentism and Eternalism. In: Erkenntnis 78.1 (2013), pp [48] Nathan L. Oaklander and Quentin Smith, eds. The New Theory of Time. New Haven: Yale University Press, [49] Robert J. Oppenheimer. Science and the Common Understanding. New York: Simon & Schuster, [50] John Perry. The Problem of the Essential Indexical. In: Nous (1979), pp [51] A. N. Prior. Time, Existence and Identity. In: Proceedings of the Aristotelian Society 66 (1965), pp [52] Arthur Prior. Now. In: Noûs 2 (1968), pp [53] Arthur N. Prior. Thank Goodness That s Over. In: Philosophy 20 (1959), p. 17. [54] Willard Van Orman Quine. From a Logical Point of View. Harvard University Press, [55] Willard Van Orman Quine. Methods of Logic. New York: Holt, Rinehart and Winston, [56] Willard Van Orman Quine. On What There Is. In: The Review of Metaphysics 2.5 (Sept. 1948), pp [57] Willard Van Orman Quine. Word & Object. The MIT Press, [58] Bertrand Russell. An Inquiry into Meaning and Truth. London: Allen & Unwin, [59] Theodore Sider. Four Dimensionalism. Oxford: Oxford University Press, [60] Theodore Sider. Presentism and Ontological Commitment. In: Journal of Philosophy 96 (1999), pp [61] Theodore Sider. The Stage View and Temporary Intrinsics. In: Analysis 60.1 (2000), pp [62] Jonathan Charles Tallant. Defining Existence Presentism. In: Erkenntnis 79.3 (2014), pp [63] Giuliano Torrengo. Ostrich Presentism. In: Philosophical Studies (2014), pp [64] Giuliano Torrengo. Tenseless Time Vs. Tensed Truthmakers. In: Proceedings of Fostering the Ontological Turn, Gustav Bergmann Frankfurt: Ontos Verlag, 2008, pp

29 Florian Fischer: Introduction 27 [65] Giuliano Torrengo. The Grounding Problem and Presentist Explanations. In: Synthese (2013), pp [66] Giuliano Torrengo. Time, Context, and Cross-Temporal Claims. In: Philosophia 38.2 (2010), pp [67] Dean Wallace Zimmerman. Temporary Intrinsics and Presentism. In: Metaphysics: The Big Questions. Ed. by Peter van Inwagen and Dean Wallace Zimmerman. Wiley-Blackwell, 1998, pp [68] Pamela Zinn. Lucretius On Time and Its Perception. In: New Developments in Philosophy of Time. Ed. by Florian Fischer. Kriterion Journal of Philosophy, 2016.

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31 Defining Original Presentism Jesse M. Mulder Abstract It is surprisingly hard to define presentism. Traditional definitions of the view, in terms of tensed existence statements, have turned out not to to be capable of convincingly distinguishing presentism from eternalism. Picking up on a recent proposal by Tallant, I suggest that we need to locate the break between eternalism and presentism on a much more fundamental level. The problem is that presentists have tried to express their view within a framework that is inherently eternalist. I call that framework the Fregean nexus, as it is defined by Frege s atemporal understanding of predication. In particular, I show that the tense-logical understanding of tense which is treated as common ground in the debate rests on this very same Fregean nexus, and is thus inadequate for a proper definition of presentism. I contrast the Fregean nexus with what I call the original temporal nexus, which is based on an alternative, inherently temporal form of predication. Finally, I propose to define presentism in terms of the original temporal nexus, yielding original presentism. According to original presentism, temporal propositions are distinguished from atemporal ones not by aspects of their content, as they are on views based on the Fregean nexus, but by their form in particular, by their form of predication. Keywords: presentism, A-theory, time, tense, predication, existence Introduction Presentists uniformly reject any view on which past and future things exist just as much as present things do. Yet it is surprisingly hard to formulate, in a satisfactory manner, what their positive view is. Indeed, a small industry has recently developed over the question how best to define presentism. The issue has become all the more urgent through, Kriterion Journal of Philosophy, 2016, 30(2): c 2016 The author

32 30 KRITERION Journal of Philosophy, 2016, 30(2): amongst other things, charges of insubstantiality [5, 15, 16, 36], and through the infamous truthmaker arguments [3, 4, 6, 7, 8, 10, 13, 19, 29, 39, 41, 42]. At bottom, the problem that the presentist faces is that the seemingly straightforward ways of defining the view in terms of a suitable, tensed existence claim, that is turn out to be either trivially true (so that they are acceptable to everyone, including eternalists) or trivially false (so that they are acceptable to nobody, including presentists). Picking up on a recent suggestion by Jonathan Tallant [39], who is in turn inspired by Trenton Merricks [29], I will propose a fresh look at the problem of defining presentism, that leads to a new definition (of sorts). My hypothesis is that whereas eternalism meshes nicely with standard logical formalisms, including tense logic, presentism in fact does not. If that is right, the problems that plague definers of presentism result simply from the fact that they are trying to formulate their view within a framework that is inherently eternalist. For reasons to be explored, I call that framework the Fregean nexus. It is pointless to try to formulate, within that framework, a coherent, non-trivial statement on which presentists and eternalists can agree to disagree. Instead, the presentist should step back and develop her views against the background of an alternative framework that doesn t exclude presentism from the start. In this paper, I argue that there is such a framework, and, moreover, that this alternative framework entails presentism. That is to say, the alternative framework is as hostile to eternalism as the Fregean nexus is to presentism. I call this alternative framework the original temporal nexus. It is inspired by Sebastian Rödl s highly original work on categories of the temporal [34]. The key to this alternative is a different form of predication different, that is, from the Fregean form of predication that constitutes the core of the Fregean nexus, and thus underlies standard logical formalisms (again, including tense logic). I sketch that alternative form of predication, and the logical categories to which it gives rise. Presentism can then be defined as the view that the original temporal nexus is ineliminable and irreducible. In other words, the difference between eternalism and presentism turns out to be a formal one (in my sense of formal see 2). I start with a brief review of recent attempts at a definition of presentism in 1, then move on to introduce the notion of forms of predication, including a characterization of the two mentioned frameworks, the Fregean nexus and the original temporal nexus, in 2. It transpires

33 Jesse M. Mulder: Defining Original Presentism 31 from these two opening sections that we need to take a thorough look at the understanding of tense that stands in the background of the debate on definitions of presentism. So, in 3, I scrutinize that understanding and show what is wrong with it: it rests on the Fregean nexus. In the final section, 4, I propose my own definition, in terms of the original temporal nexus. 1 Defining Presentism Eternalists say that everything past, present, and future exists. Presentists deny this: only present things exist. They say that past things are no more, while future things are not yet. 1 Since these claims look like existence claims, it is natural to start formalizing them using the existential quantifier, in order to arrive at a substantial existence claim that eternalists and presentists unequivocally disagree on. Further progress in the debate between eternalists and presentists can then be made by spelling out exactly what it takes to endorse that claim or its negation. Or so it is thought. Before we assess this strategy, three preliminary remarks on terminology are in order. First, I adopt a broad conception of A-theory any view on which tense is metaphysically fundamental (in some sense) qualifies as a version of A-theory in my sense. 2 Second, I take presentism to be a version of A-theory; the existence claim that presentists are looking for to identify their position will thus have to be read tensedly. And third, I conceive of presentism s opposite, eternalism, rather broadly as well encompassing both the more orthodox, B-theoretic versions of the view and also A-theoretic versions such as moving spotlight theory. 3 Now, Meyer [30] challenges the presentist as follows. 4 He takes the following proposed definition of presentism as his starting point: P Nothing exists that is not present. [30, p.213] 5 P is ambiguous in its tense, for exists can be read in two ways. Disambiguation yields the following two alternatives: P1 Nothing exists now that is not present. P2 Nothing exists temporally that is not present. [30, p.214] P1 is trivially true, and is thus of no help to the presentist. The alternative is to render exists as temporally general: has existed, exists, or will exist. That is what P2 expresses, which is clearly absurd: Julius

34 32 KRITERION Journal of Philosophy, 2016, 30(2): Caesar, for instance, existed, but is not present. Thus, presentism is either trivial or absurd. 6 If these were the only options for the presentist, the view would indeed be doomed. For P1, being trivial, fails to capture a distinctive position, while P2 amounts to the absurd thesis that reality is just one snap-shot: it is what we get if we take the eternalist s time line and simply erase everything except for the present moment. It seems that Lewis thought of presentism along the lines of P2 hence his dismissive observation that presentism denies time altogether (see [23, p.204] and [24, p.2]). Serious presentists will want to say that this is a straw man let us call the straw man position negative presentism. They are under pressure to define their view differently. Crisp develops an alternative reading of P2 which is carefully crafted so as to be solve this dilemma [11]. In particular, he thinks counterexamples to P2, like Julius Caesar existed but is not present, can be rejected if we take care to properly delineate the domain over which the temporally general quantifier in P2, exists temporally, ranges. 7 He urges us to distinguish between a de dicto and a de re reading of such alleged counterexamples to P2, which he renders as follows (where t α denotes the present time): RE 1 WAS(for some x, x is Julius Caesar and x will not exist in t α ) RE 2 For some x, x was Julius Caesar and x is no longer present [11, p.18; example adapted] The point, then, is that RE 1 is obviously true but doesn t provide the kind of counterexample that turns P2 into a falsehood, whereas RE 2 is not obviously true (or false) at all. It seems that the eternalist has to accept RE 2, while the presentist denies it. The key to Crisp s definition is a dynamic conception of the domain of quantification: it used to contain Julius Caesar, but doesn t anymore. 8 If we think of the domain as representing reality, it appears that we do get a presentist picture: only present things exist. Unfortunately, as Tallant shows, Crisp s attempt still falls prey to a Meyer-style objection [39]. For what is the tense of the quantifier in RE 2? Following Meyer, the options Tallant presents are in terms of present existence ( n : exists now) and temporal existence ( t : existed, exists now, or will exist): RE 2a n (x was Julius Caesar and PRES x)

35 Jesse M. Mulder: Defining Original Presentism 33 RE 2b t (x was Julius Caesar and PRES x) [39, p.481; example adapted] It seems that the presentist has to be in agreement with the eternalist on both RE 2a and RE 2b: the first is trivially false, while the negation of the second is, again, untenable: Julius Caesar did exist, so the quantifier t does range over him. 9 Again, if these are the only options for the presentist, the view is doomed as it has to choose between a triviality on the one hand and the absurdity of negative presentism on the other. But Tallant has more to say. His aim, like mine, is to provide a novel definition of presentism. His proposal is, as we will see shortly, to switch from existence claims to a claim about existence. He takes his cue from the following passages by Merricks: Presentists and eternalists alike say that those things that exist at the present time really do exist and, moreover, that properties had at the present time really are had. Thus one might think, whilst presentism and eternalism part ways with respect to other times, they agree about the nature of the present time, and, relatedly, agree about what it is to exist (and have properties) at the present time. But they do not agree about these things. Indeed, their differences with respect to the nature of, and existence at, the present time are as important as their differences with respect to the past and future. [29, p.123] Since they do not believe in a region called the present time, presentists cannot reduce existing at the present time to being located at that region. I think presentists should, instead, say that existing at the present time just is existing. [29, p.125] 10 Tallant comments on these passages as follows: It seems right that presentism ought to be understood, not merely as a thesis concerning the number of times that exist, but also as a thesis with a commitment to the nature of those times. [39, p.493] This sounds promising. Perhaps the presentist only seems to be stuck between a triviality and the absurdity of negative presentism as long as she assumes the eternalist s understanding of what it means to enjoy

36 34 KRITERION Journal of Philosophy, 2016, 30(2): temporal existence. Negative presentism indeed accepts the eternalist s take on temporal existence and merely restricts the number of times, as we saw. So perhaps we can escape from triviality and absurdity if we manage to provide a positive account of the nature of time, of what it means to exist in time, that differs from the eternalist s. Tallant s proposal is an attempt to do so. He develops his own formulation of what he takes to be the thought underlying Merricks s remarks 11, leading to what he calls Existence Presentism (where presence is to is present what existence is to exists ): EP Presence is existence [39, p.494] Here, Tallant says, the is is to be read present-tensed (so no Meyerinspired potentially threatening disambiguation of the copula is possible). EP is not trivial: past things are not present, hence, by the identity of presence with existence, they don t exist. Eternalists have to disagree here. Moreover, EP is not obviously false either. Thus, it seems that EP does not fall prey to Meyer s complaint. As I announced earlier, we have indeed shifted from existence claims proper to a claim about existence. 12 I think Tallant s solution is on the right track. It points us towards a positive, non-eternalist account of the nature of time, of what it means to enjoy temporal existence, in the following way. The eternalist holds that existence is an atemporal notion, which acquires a temporal dimension by being linked to times (which can be done either B-theoretically or A-theoretically; see 3 4 below). On Tallant s proposal, existence becomes an inherently temporal notion, and therefore no longer requires being linked to times. 13 Yet a worry remains. For how should we understand the kinds of claims that refuted the other proposals I surveyed past existence claims such as Caesar existed? Presumably, we should render that claim as follows: WAS(Caesar exists). By EP, that should be equivalent to WAS(Caesar is present). Now, if is present here functions rigidly (like the actuality operator in certain modal logics) this is clearly false: it was never the case that Caesar is (now) present. So the temporal operator WAS affects the contribution that is present makes to a statement. And that seems to suggest that the property which the phrase is present in the statement WAS(Caesar is present) denotes is different from the property it denotes in the statement Tallant is present. Perhaps the difference is that the latter denotes the property of being-present-now, while the former denotes the property of havingbeen-present? And if so, given that there has to be some kind of intimate relation between these two different presence-properties, it is natural to

37 Jesse M. Mulder: Defining Original Presentism 35 say that the same should hold for the existence-property with which one of them is identical differentiating it into existing-now and havingexisted. This line of thought reduces EP to a triviality after all: of course existing now simply is being present-now, while having-existed simply is (or was) having been present every eternalist would agree. (And the radical alternative denying that Caesar existed again moves us back to the absurdity of negative presentism.) But perhaps the worry can be laid to rest if we can clarify how exactly the WAS -operator works in a way that prevents this multiplication of presence-properties. That is, we should now discuss A-theory, the thesis that tense is fundamental, and, in particular, its relation to the presentism eternalism issue. 14 On this point, Kit Fine has argued that a proper understanding of A- theory in fact motivates a rejection of presentism. He puts the thought as follows (where his ontic presentism is what I ve been calling, following tradition, presentism ; while his factive presentism is what I call A- theory): Ontic presentism is an ontological position; it is a view about what there is. Factive presentism, on the other hand, is a metaphysical... position; it is a view about how things are, quite apart from what there is.... Moreover, ontic presentism is a negative view; it excludes certain things from what there is. Factive presentism, on the other hand, is a positive view; it includes certain ways of being in how things are.... It is readily possible for a factive presentist not to be an ontic presentist. Indeed, he may endorse a full ontology of things past, present, and future: all such things may figure in his preferred account of reality.... He merely insists that some of the facts (if not all) should concern how things presently are. I am inclined to think that this version of factive presentism is much more plausible than the usual version, in which only present things are taken to exist; and it is a shame that a one-sided conception of the presentist issue has prevented philosophers from taking it more seriously. [18, p.299] If Fine is right in thus contrasting presentism and A-theory (or, in his words, ontic and factive presentism), then tensing their statements is not going to help the defender of presentism. But Fine is wrong. As I will argue below (in 3), Fine s liberal standpoint with respect to eternalism results from his implicitly accepting the

38 36 KRITERION Journal of Philosophy, 2016, 30(2): eternalist s understanding of temporality. That implicit acceptance infects his understanding of tense which he inherits from Arthur Prior s tense logic. Whether or not temporal facts are tensed in this infected sense is of no help to the presentist: the ensuing A-theory is a mere variant of the underlying, eternalism-friendly understanding of time. It is not surprising that attempts to define presentism on such a basis fail. Before I turn to a critical examination of the understanding of tense underlying the debate on the definition of presentism, I first have to introduce the alternative understanding that underlies my own proposal. Juxtaposing the prevailing conception of tense with this alternative will help make clear where exactly things go wrong. 2 Forms of Predication The above dialectical exercise motivates the search for a more fundamental point of divergence between eternalists and presentists which is, in fact, what Tallant, following Merricks, has also been looking for. Put somewhat cryptically, my suggestion is that we need to switch the logical background against which we attempt to define presentism. Let us first have a brief look at the prevailing logical background. The basis is Fregean: predicate logic. Underlying this logic, we find a certain form of predication: the one that Frege took to be analogous (or even identical) to mathematical function application [20, 21]. That is, the Fregean form of predication unites any given concept (Begriff ) with a fitting number of objects (Gegenstände) to yield a unique proposition (Gedanke) that is either true or false. Thus, to this form of predication there corresponds a system of categories or formal concepts, in this case the categories of Begriff and Gegenstand. They are formal in the sense of being defined by the described form of predication. Together, these formal categories constitute what I call the Fregean nexus. My use of form here requires a bit of clarification.i focus on the form which a proposition has in virtue of the form of predication it embodies. That is an unusual sense of form. Usually, with form one means to denote the diverse forms Fregean propositions can take, depending on the occurrences of logical constants and on the adicity of the predicates involved. I, however, want to focus on differences in form based on differences in form of predication. E.g., F a, Rab, and F a Gb all have different forms on the usual notion of form, but they have the same form in my sense: they all involve Fregean predication; F, G, and R fall under the formal category Begriff ; and a and b fall under the formal

39 Jesse M. Mulder: Defining Original Presentism 37 category Gegenstand. This way of looking at the form of propositions is unusual because alternatives to the Fregean form of predication are only very rarely considered. The Fregean nexus is atemporal: time plays no role in its categories. Typical examples of the Fregean form of predication are atemporal e.g., 3 [is] a prime number (where [square brackets] indicate the Fregean, atemporal form of predication). The Fregean nexus lends itself to the kinds of formal systems that analytic philosophers are fond of. Predicate logic can of course be extended in various ways, for instance, by adding modal operators or tense operators. Such extensions do not change the underlying form of predication as I will argue in the next section below. Since time plays no role in the form of Fregean propositions, it can only play a role by being introduced as bits of content. Temporal propositions are then distinguished from atemporal ones not by form, but by content. The most straightforward way of doing so is by adding argument places for times: e.g., the colloquial The cat is on the table gets analyzed as The cat [is] on the table at t. 15 Thus, temporal propositions are ordered in a series by way of these temporal indices, and the result is (a version of) B-theory. 16 As we will see in the next section, tense logic is another, less straightforward way of supplementing atemporal Fregean propositions with features that yield the right kind of ordering. In both cases, the formal basis is the Fregean nexus, and the temporality of temporal propositions is accounted for by the relevant ordering. That is the hallmark of eternalism: if something exists, has existed, or will exist, there will be a suitable atemporal proposition relating it to the relevant point on that ordering stating, in effect, that it [exists] at t. In other words, the Fregean nexus is inherently eternalist. There is, however, a quite different form of predication that is adequately described as being temporal. It gives rise to a different (larger) set of categories. It does not obviously lend itself to the kinds of formal systems that analytic philosophers are used to, which are invariably based on the Fregean form of predication. Propositions that exemplify this temporal form of predication are thus temporal not by content, but by form (in my sense). In fact, we are all very familiar with this form of predication. Consider the following sentences: T1 The cat is on the table T2 The cat was on the table T3 The cat is jumping to the ground

40 38 KRITERION Journal of Philosophy, 2016, 30(2): T4 The cat was jumping to the ground T5 The cat has jumped to the ground T6 The cat can jump (or: The cat jumps) Three observations are in order. First, a familiar one: T1 and T2 unite the very same concept (being on) with the very same objects (the cat, the table), but they are different they are differentiated in tense. I illustrate what this differentiation exactly amounts to below, from which it will become clear that it is impossible to model is on and was on as simply two different concepts in the Fregean sense. Secondly, a perhaps less familiar observation: T3, T4 and T5 also unite the same objects with the same concept in different ways, but here the differentiation is not merely in tense but also in aspect, with T3 and T4 being in progressive aspect while T5 is in perfective aspect. And, as has been repeatedly observed, T5 implies T4, but not vice versa, for the following may occur: while the cat was jumping to the ground, I caught it in mid-air so that it is not the case that the cat has jumped to the ground. 17 Thirdly, and finally, there is another way in which activities may be joined to objects, in English expressible by use of a habitual sentence, as in T6: it unites them in a time-general way that is, in fundamental cases, not differentiated in tense or aspect. It is linked to the aspectual forms by entailment: from any sentence of the form T3, T4 or T5 the corresponding version of T6 follows. 18 Thus we have a richly interrelated array of sentence-forms; because of those interrelations I regard them together as guises of one and the same form of predication (just as I consider predications of any arity to be exemplifications of one and the same Fregean, atemporal form of predication). It is apt to call this form of predication temporal predication. In this paper, I focus on how recognition of this form of predication may contribute to a proper definition of presentism. For that purpose, one observation is of particular importance, namely, that differentiation in tense is not as straightforward as it seems. It is not that, using different tenses, one can construct different propositions from the same materials. For, in the right circumstances, it may be that one says the same thing by uttering, e.g., first T1, then T2. One way to illustrate this is by considering disagreement: if A yesterday said The cat is on the table, then B can challenge his statement today by saying the cat was not on the table. 19 And likewise, one can say different things by uttering T1 at different times. That is, the linguistic

41 Jesse M. Mulder: Defining Original Presentism 39 forms of the sentences T1 T2 do not correspond to the logical forms of the temporal propositions they express. 20 At this point, we can simply register this as a peculiarity of temporal predication: different sentences are required to express the same temporal proposition at different times. 21 We should resist the temptation to settle on a formulation (or formalization) designed to capture the form of the relevant proposition in abstraction from this peculiarity it is simply the condition of stating (or thinking) temporal propositions in time that enforces the use of differently tensed sentences. I dwell on this point because it is not in line with the very paradigm understanding of tense that underlies most contemporary versions of A-theory, hence also of presentism: Prior s tense logic. In that logic, the basic temporal bearers of truth are present-tensed atomic propositions that can differ in truth value over time. As I argue below, this assumption only makes sense if these basic temporal bearers of truth bear the form of Fregean propositions. And that is, I submit, the root of the difficulty of finding an appropriate definition of presentism. Anyway, as in the case of Frege s atemporal predication, we may extract certain categories (formal concepts) from this temporal form of predication. Firstly, and most straightforwardly, we have the category of substance (corresponding to Frege s Gegenstand). 22 Secondly, we have, corresponding to Frege s Begriff, two categories of predicables: feature/relation (such as being round and being on ) and activity (such as jumping ). The difference between these two is indeed formal: activities occur in aspectually differentiated propositions, while features cannot. It is perhaps useful to take this more slowly in order to clarify the way this lifting of categories from a form of predication works. Frege thinks that the form of a thought any thought is based on his undifferentiated form of predication: predication as function application. Thus, the basic elements of thought are defined by this form of predication. It differentiates between objects and concepts, and therefore these two categories can be lifted from his form of predication. The temporal form of predication I have introduced is, unlike Frege s, differentiated. Suppose that it is the form of temporal thought as such all temporal thought shares this form. Then, just as in the Fregean case, the basic elements of temporal thought can be lifted from this form of predication. As it is differentiated in tense and aspect, it gives rise not just to two but to three categories: substance, feature/relation, activity. These are, then, formal notions in the same sense as Frege s categories of Gegen-

42 40 KRITERION Journal of Philosophy, 2016, 30(2): stand and Begriff are formal notions. In Frege s case, this gives rise to observations such as that one cannot predicate the object 5 of the object 6. The form of predication forbids it. Likewise, in the case of temporal predication, one cannot predicate is round of the ball in an aspectually differentiated way, nor can one predicate jump of the cat in the manner of a feature. The form of predication forbids it. Now, given its differentation, the temporal form of predication allows for a perspective that is unavailable in the case of Frege s undifferentiated form of predication. The temporal form of predication includes three fundamentally different ways of joining appropriate elements together: in a tensed way (T1 T2), in an aspected way (T3 T5), and in a time-general way (T6). Temporal thoughts are thus differentiated into three kinds: the tensed ones, the aspected ones, and the time-general ones. (We noted that these are not independent.) One can label the first passage, the second process (or change, or causality), and the third potentiality (or power). I should repeat: the content of these notions lies solely in the distinctions that the temporal form of predication allows for. 23 This perspective on the form of temporal thought is unusual I have frequently found it to meet with incomprehension. In the context of this paper, I can do no more than sketch its outline; for a mcuh more thorough articulation and defense of these categories themselves as well as of the understanding of logic and metaphysics that underlies it, I have to refer, again, to Rödl s seminal work Categories of the Temporal [34]. Interesting further questions concerning these categories and their interrelations can be asked: for instance, the dependence of aspect on tense is clear from examples like T3 T5, but what about the other direction? Is tense conceivable without aspect? In effect, the question here is whether there can be passage of time without change. (The answer is no, but I won t argue for that claim in detail here however, see [34, chpt.5, esp. 4].) This indicates the ambition that lies behind the recognition of temporal predication as providing a logical framework different from the prevailing Fregean one: the framework it provides allows one to formulate metaphysical questions and views concerning a considerable range of topics related to time and causality such as change, identity, persistence, and essence, to name the more obvious ones. 24 These categories of the temporal together constitute what I call the original temporal nexus: an interdependent cluster of formal concepts. If it is apt to call the system of forms to which Frege s atemporal form of predication gives rise a logic (or a family of logics), then it is equally

43 Jesse M. Mulder: Defining Original Presentism 41 apt, though perhaps unusual, to call the system of forms to which the temporal form of predication gives rise a logic. My proposal is, thus, to take this logic, and not the Fregean one, as the proper logical background for the project of defining presentism. Therefore, I have to ask the reader to not immediately think of the above considerations and the ensuing original temporal nexus as standing in need of analysis in more perspicuous terms (such as tense logic). For what I am after is precisely to define presentism in terms of the irreducibility of this temporal form of predication. On a very abstract level, the irreducibility claim can be defended by noting, with Rödl, that nothing the apprehension of which does not involve the deployment of a given form of thought can justify its application [35, p.53]. That is, if certain propositions can be apprehended without using the system of forms the original temporal nexus provides, then there can be no justification for its subsequent application to those propositions. E.g., we apprehend mathematical truths, such as = 4, by using the Fregean form of predication. And that prevents the original temporal nexus from being applicable: rephrasing = 4 in temporal terms gives only the semblance of a proposition, but in fact is without sense. So any account of time in terms of the Fregean form of predication amounts to a proposed elimination of the original temporal nexus. Presentists should resist such elimination, on the ground that it amounts to an elimination of time itself. This ineliminability claim is the core thesis of what I call the original view: it takes temporal propositions to be differentiated from atemporal propositions by their form (in my sense of form ), which is the temporal form of predication. In 4 below, I will discuss how the original view relates to presentism. A considerable obstacle for appreciating my proposal stems, interestingly, from Arthur Prior s tense logic despite his unrelenting engagement for presentism. I have already hinted towards the flaw that his tense logic-based conception of tense incorporates. That flaw takes center stage in the next section, after which I will return to my topic, the definition of presentism, in the final section, 4. 3 Tense and Tense Logic As we have seen in the first section, definitions of presentism essentially make use of tensed statements. We saw that definitions of those shapes are deemed unsatisfactory precisely because the tensed statements they

44 42 KRITERION Journal of Philosophy, 2016, 30(2): involve are equi-acceptable to presentists and eternalists: apparently, the underlying conception of tense is neutral with regard to the presentism/eternalism controversy. At the end of that same section, I quoted Fine s remarks in favor of factive presentism (that is, generic A-theory) and against ontic presentism (that is, presentism): according to Fine, the A-theorist insists on temporal facts having a fundamentally tensed form, so to speak, but does not necessarily wish to deny the existence of past and future things. Fine s conception of tense is thus equally neutral with regard to the presentism/eternalism controversy. It is useful to see what exactly his conception of tense amounts to, for it is not the one that finds its home in the original temporal nexus. Rather, it ultimately rests on the Fregean, atemporal nexus, and is thus inherently eternalist. Fine distinguishes three versions of A-theory, 25 all of which state that temporal facts are (or at least include such that are), fundamentally, tensed facts of the forms captured in Prior s tense logic: p (presenttensed), Pp (past-tensed), Fp (future-tensed), etc. Consider, now, a standard, B-theoretic eternalist picture: it comprises the full collection of tenseless B-facts, ordered on the time line by the relevant (temporal) aspects of their content. What happens if we replace all these B-facts with tensed facts in this Priorian sense? The first thing to note is that Priorian tensed facts, unlike B-facts, do not tell us where they are located. Their ordering is lost. Hence the A- theorist needs a way of anchoring such facts to the right moments. The most familiar way is what Fine calls standard A-theory: it privileges the present time and replaces all the B-facts with A-facts oriented towards that time. But that is not the only option: as Fine shows, one can also be a non-standard A-theorist by rejecting such privileging of one point in time. That means that not only the tensed facts oriented towards the present time are included in reality, but also all the tensed facts oriented towards all the other times. Thereby, incompatible facts are included in reality: if yesterday p was true while today p is true, then both p and p are included in reality. Again, their ordering is gone. There are, now, two ways of dealing with this situation. The first is to relativize reality: each point in time has its own reality. Thus, the unity of reality is given up in order to sort the tensed facts to their proper locations. The second option is to endorse the incoherence of reality. The incoherence can then be locally resolved by saying that the incoherent über-reality decomposes into coherent fragments. Fine calls the first option external relativism and the second option fragmentalism. 26

45 Jesse M. Mulder: Defining Original Presentism 43 The details of these non-standard views do not matter much for present purposes. What does matter are the following observations. First, the standard A-theorist s reality is in its entirety included in the realities of the non-standard realists either as one of the many relative realities, or (arguably) as one of the many fragments of the one incoherent über-reality. Secondly, and relatedly, the non-standard views incorporate many different versions of what are, from the standpoint of the original temporal nexus, the very same fact: for instance, yesterday s p and today s Pp. Thirdly, and most importantly, this raises the question as to why we should expect the many realities or fragments to mesh in the expected way: why can it not happen, for instance, that today s reality contains Pp even though all earlier realities contain p? This worrying question and, indeed, the entire possibility of nonstandard A-theories rests on the time-relativity of truth that is inherent in the Priorian conception of tense. Prior s tense logic captures only the interrelations between tensed statements from one and the same temporal perspective, but it doesn t capture their cross-temporal sameness. That is, Prior is expressing something that goes beyond his own logic when he writes: In tense logic the totalities of tensed propositions which are true at different instants fit together into a system, so that although the total course of history will be differently described at different times, the description at one time will determine what the descriptions at other times will be. [33, p.38] Take, for instance, a simple present-tensed proposition p that is presently true. Using tense logic, one can infer that, therefore, it will be the case that it was true: FPp (ϕ FPϕ is included as an axiom in virtually all tense logics). These two formulae are both presently true. One day passes: the proposition Pp is now presently true, from which we can infer, e.g, that PFPp is (presently) true (though not on the basis of the same axiom). But these two collections of truths are logically entirely independent: there is no way to connect yesterday s truths (p, and FPp) with today s (Pp, and PFPp) using the resources of tense logic. 27 Considering an intellect capable only of grasping thoughts of these tense-logical forms, Rödl puts this point as follows: Such an intellect is a totality of tense-logical contents, wherefore the system of these totalities is not accessible to him. One instance follows the other, and with it one totality takes

46 44 KRITERION Journal of Philosophy, 2016, 30(2): the place of the previous one.... The meaning of a tenselogical sentence resides in the conditions under which ispresent true applies to it, and these are different at different times. Hence, as time passes, the meaning of all tense-logical sentences shifts.... Since the meaning of all of his sentences shifts, he has no means to say that it shifts. [34, p.106] Analogously, we may say that a tense-logical reality is a totality of tenselogical facts (Fine s varieties of A-theory are varieties of this thesis). What this means is best seen when we consider Fine s external relativist version of A-theory. On that view, there are different realities that contain instances of the same fact; e.g., yesterday s reality contains p, today s reality contains Pp. However, that yesterday s p is identical with today s Pp (or, if you prefer, that they express the same fact) is something that cannot be included in those realities as additional tenselogical facts. For one thing, the cross-temporal sameness of these additional facts will then once more stand in need of being included by way of further facts of cross-temporal fact-sameness, leading to a regress. 28 And for another thing, tense logic simply has no resources for saying that p and Pp are (or express) the same fact: to do so, one would need a fact connecting facts from two different realities (in the case of external relativism) and to which reality would such a fact belong? Let us take this a little bit slower. The defender of tense logic might say, speaking about tense-logical formulae from a meta-perspective: p s past truth is mirrored in Pp s present truth, and that is ensured by FPp s past truth. 29 Now, assume that this statement itself is a statement bearing tense-logical form. Focus on the first bit: what would it be to talk, tense-logically, about p s past truth? The notion of past truth will have to be explained in tense-logical terms: p was true in the past is true just if Pp is true. That is, the notion of past-truth just is the past-operator P. So the first bit of our statement says, in effect, that Pp is mirrored in Pp. Saying that p was true does not get one beyond saying that Pp is true. Thus, such an attempt to formulate the cross-temporal interdependencies of time-relative truth, if read as itself a tense-logical statement, simply says something that is-present-true of the sentences (or formulae) p, Pp, and FPp. It expresses how various present-truths and present-falsehoods, concerning which formulae were, are, and will be true, hang together. That does not tell us how their present-truths and present-falsehoods hang together with truths and falsehoods at other moments. What we attempt to say about this turns out to be, again, present-true or present-false at least, as long as we are required to

47 Jesse M. Mulder: Defining Original Presentism 45 move within the realm of tense-logical forms. The point is that, by making truth time-relative, as tense logic does, one is simply deprived from the means of saying anything whatsoever about what is true at other moments. We always and invariably end up saying what is-presenttrue about what is-past-true (or future-true). We require, for instance, that p s past truth be reflected in Pp s present truth. That requirement, if it is to state what we want it to state, cannot itself be a tense-logical statement. 30 Fine s non-standard versions of A-theory bring out this crosstemporal independence indeed, they are only possible because of this independence. On standard A-theory, one could argue that all there is is the present-truth of past- and future-tensed propositions; all there is is tensed facts oriented towards the present. Fine shows that this is optional: one can also endorse versions of A-theory that deny this priviledging of the present moment, thus making room for all of the tensed facts oriented towards other moments as well. The totality of tensed facts oriented towards the present is then completely disjoint from the totality of tensed facts oriented towards earlier and later moments (although in the case of fragmentalism they may overlap). Indeed, to repeat Rödl s way of putting things, one instance follows the other, and with it one totality takes the place of the previous one. There is no way of saying anything about how those totalities relate using tense-logical forms. One might try saying that we should thus simply reject Fine s nonstandard forms of A-theory. But the point is, precisely, that the underlying understanding of tense allows for them. An adequate understanding of tense should rule out such forms of A-theory it should incorporate the cross-temporal integration that Prior s tense logic fails to capture. The understanding of tense embodied in tense logic is thus not the one we found in the original temporal nexus. If my sketch of the Fregean, atemporal and the original, temporal forms of predication is right, one expects that anything falling short of the temporal form of predication (such as Prior s tense logic) must rest on atemporal predication. And so it does. To see why, it is helpful to reconsider negative presentism the view that takes the eternalist s time line and erases all but the present moment. A would-be negative presentist will claim that the truths concerning the one moment he acknowledges (the present) are present-tensed truths. But why, we may ask, are these present-tensed truths and not simply atemporal truths (exemplifying the Fregean form of predication)?

48 46 KRITERION Journal of Philosophy, 2016, 30(2): The negative presentist can do nothing to distinguish his view from an eternalist, B-theoretic view of a temporally thin reality. 31 The underlying problem here is, again, nicely stated by Rödl: [If] a present tense formula is elementary, then the contrast to the corresponding past tense formula is not part of its [content], and without this contrast, present has no temporal meaning. [34, p.107] The original temporal nexus does include that contrast in its conception of temporal truth: differently tensed sentences do not state differently tensed propositions whose truth (or falsehood) is time-relative rather, temporal propositions whose truth (or falsehood) is time-absolute have to be expressed by using suitable, differently tensed sentences as time passes. 32 Consider, by way of analogy, a reductive view of modality like Lewis s [23]. What is crucial, for such a reductive project, is to isolate modality completely. In its simplest, propositional form, that is achieved by establishing a stock of a-modal elementary propositions, p, q, etc., to which modal operators can then be prefixed in order to make modal statements. The elementary propositions are true or false, and can be understood, in complete independence from their modalized versions. The reduction then proceeds by analyzing the modalized versions in terms of their elementary counterparts at other worlds. The result is a relativization of truth to worlds. Something similar happens in the case of tense logic: there is a stock of atemporal elementary propositions, p, q, etc., to which tense operators can be prefixed in order to make tensed statements, that can subsequently be reduced to their atemporal counterparts at other times. The result is a relativization of truth to times. Prior, of course, both resisted the reduction and insisted that the elementary propositions are present-tensed but, again, mere insistence is not enough. What is required is the kind of temporal integration that, as we saw, is precluded by relativizing truth to times. In other words, what is required is the signature of tense that the original temporal nexus recognizes. The fundamental claim of eternalism is that time is the time-line: temporal propositions are internally atemporal, that is, they have an atemporal form; their temporality consists in their being suitably ordered, in some way or other. As we have seen, there are various ways of spelling this out. Standard B-theory is one such way: it incorporates temporality, in the end, by way of an extra piece of content a specification of the temporal location. Fine s versions of A-theory are other such

49 Jesse M. Mulder: Defining Original Presentism 47 ways despite appearances. Even negative presentism is one such way, though a limiting case. Unfortunately, for Prior, his attempt to arrive at a genuinely non-reductive logic of tense thus turns out to provide excellent materials for a sophisticated reductive understanding of tense. These considerations shed a new light on my survey of attempts to arrive at a definition of presentism in the first section above. As long as tense is conceived so as to be consistent with this fundamental eternalist claim, it does not matter whether the quantifiers are tensed or not: we will remain stuck with statements that are either trivial, because they are restricted to the present moment, or absurd, because they restrict the whole time line to the present moment. Again, what we need is not a different view on the number of times, but rather a different view on what it is to exist in time, that is, on the nature of time (as Merricks and, following him, Tallant, suggest). The original temporal nexus promises to deliver such a different view on the nature of time as I hope to show now. 4 The Original View and Presentism Our situation is as follows. Attempted definitions of presentism were unsatisfactory because they failed to deliver an unambiguous thesis on which presentists and eternalists could disagree. This motivated a look at the logical background against which the search for such a definition proceeds. That logical background is biased towards eternalism: its core is the Fregean nexus, which rests on an atemporal form of predication. My discussion of the tense-logical understanding of tense, which is supposed to provide a presentism-friendly alternative to B-theory, underwrites this conclusion: it too rests on the Fregean nexus. I contrasted the Fregean nexus with the original temporal nexus, which rests on an alternative, temporal form of predication. The original view takes this original temporal nexus as its starting point. We now need to understand how presentism relates to the original view. As said, eternalism does not take the temporality of temporal propositions to consist in their having a distinctive form; temporal propositions are formulable using the familiar, Fregean atemporal form of predication. Thus, the temporality of temporal propositions consists either in some aspect of their content, such as an explicit or implicit reference to a temporal location, absolute or relative, or it consists in some other feature such as their truth (or falsehood) being time-relative. In all cases, time enters the picture by way of a time line (or a similar order-

50 48 KRITERION Journal of Philosophy, 2016, 30(2): ing) on which temporal propositions are to be anchored. And the same holds for the objects such propositions are about: they are objects existing in time by being located on certain location(s) on the time line. Their respective locations are revealed once we have the full analysis of temporal propositions concerning them before us. That is, in the case of classical B-theory, the locations of the objects are given as the temporal references included in such propositions; in the case of A-theoretic versions of eternalism, the locations of the objects figuring in temporal propositions transpire from their position on the ordering grounded in the assumed time-relativity of truth. Therefore, understanding temporal propositions as involving the Fregean, atemporal form of predication implies that for any temporally existing thing x, one can always formulate a true, atemporal proposition of the form x [exists] at t (recall that I use [square brackets] to indicate the atemporal form of predication). 33 And that, one might say, is the core thesis of eternalism. By contrast, the original view does take the temporality of temporal propositions to consist in their having a distinctive form namely, the temporal form of predication (with its many guises). One may, of course, position propositions of that form on a time line, as is done in chronological overviews of many types, yet the crucial difference is that one does not thereby explain their temporality. This holds also for existence statements: saying Caesar existed, I am reporting the very same temporal proposition that a contemporary of Caesar could have said by saying Caesar exists. 34 I can even say Caesar existed at t. But due to formal mismatch, there is no proposition of the form Caesar [exists] at t, and thus temporally existing objects in the sense of the original view (that is, substances) simply cannot function as inhabitants of the eternalist s time line. The formal mismatch arises as follows. The core thesis of eternalism I mentioned that for any temporally existing thing x, there is always a true, atemporal proposition of the form x [exists] at t is only formulable using the Fregean, atemporal form of predication. If we depart from the original view, no such statement is formulable. For suppose we start with Caesar existed : Caesar, here, names a substance a category defined by the temporal form of predication. If we replace it with Caesar [exists] at t, we are doing more than just replacing the form of predication involved. We also change the logical character of the name Caesar in this context, it is a name for a Fregean Gegenstand, a category defined by the atemporal form of predication. That Gegenstand cannot be identical with a substance for the same reason why

51 Jesse M. Mulder: Defining Original Presentism 49 an individual thing cannot be identical with a property: they belong to different categories. Not only the form of predication, but also the formal categories of the things it applies to (substances, features, relations, activities) rests on the original view. 35 From these considerations, it transpires that eternalism is only formulable within the Fregean nexus. My claim is, now, that presentism is only satisfactorily formulable within the original view. In particular, eternalism is formulable within the Fregean nexus because that nexus includes an atemporal notion of existence. Negatively speaking, then, on the original view presentism can be defined in terms of the rejection, on formal grounds, of a tenseless notion of existence (at least as applied to temporally existing things). Temporal propositions just do not have the right form to allow for anything resembling a statement of eternalism. From the perspective of the original view, then, the first thing to ask when confronted with a putative definition of presentism is: what is the form of the proposed defining statement? Take, for example, Meyer s target definition of presentism, with which I started my investigations: P Nothing exists that is not present. [30, p.213] Meyer challenged this claim on the grounds that it is either trivial (on a present-tensed reading of exists ) or untenable (on a temporally general reading of exists ). So there seemed to be no room for a distinctively presentist reading of P. But which form of predication is used? If we are to understand Meyer s tensed quantifiers along tense-logical lines, we are already in eternalist territory, and the game is lost before we even got started. Now, reading P as involving temporal predication, it still holds good only on its present-tensed reading and it is, indeed, still trivial. That, however, is no longer a problem, for the defender of presentism can point to the difference in form of predication to mark off his position from the eternalist s, who is committed to there being temporal propositions of the form x [exists] at t. In other words, the point of endorsing P, for a defender of the original view, lies in endorsing the form of predication it exemplifies. And that is not trivial at all. An eternalist reads P differently: he understands the present tense, ultimately, in terms of a location on his time line. Taken as intended by the defender of the original view, then, P does suffice to generate a difference between presentism and eternalism, albeit in a rather roundabout way, namely, by exemplifying the original temporal nexus. 36 This sort of definition of presentism, in terms of an existence statement involving the temporal form of predication, is, thus, trivial in a

52 50 KRITERION Journal of Philosophy, 2016, 30(2): peculiar way. What the defining statement says its content is trivial; its real contribution lies in the form it displays. Moreover, that form prevents an eternalist from recognizing its trivial contents the eternalist rejects the temporal form of predication. True, she can make a seemingly very similar statement, using the same form of words, and thereby express something that is trivial by her own lights involving the Fregean, atemporal form of predication. But that does not affect the proposal, of course. The triviality objection against definitions of presentism, with which I started this paper, thus does not get off the ground. In any case, such a proposal isn t very helpful: the fundamental point of disagreement between eternalism and presentism is only implicit in it, not explicit. Things are different with Tallant s proposal, which is not in terms of an existence statement but rather in terms of a statement about existence: EP Presence is existence [39, p.494] This definition comes closer to making explicit what is only implicit in my original view based rendering of P. It says what existence is, for temporal objects. 37 But, as I suggested at the end of the first section, this definition seems to leave room for a worry, since it is unclear how we should understand past existence claims such as Caesar existed. Such a claim is plausibly rendered WAS(Caesar exists), which is, by EP, equivalent to WAS(Caesar is present). Now, my worry was that it is unclear whether is present here denotes the same property that it denotes in the context of, say, Tallant is present. We can now see that that worry only makes sense if we adopt an eternalist point of view on which temporality is to be accounted for in terms of being located somewhere on the time line. From that point of view, there are two options. Either is present in the final analysis always denotes the property of [existing] at the present moment, in which case it will not be true to ascribe that property to Caesar (for he doesn t exist now); or, on the other hand, the property is present denotes shifts along with the tense operator WAS, in which case it looks like EP turns into a triviality. But we can resist this eternalist rendering of EP: instead, we can interpret it from the logical perspective of the original view. On that view, EP implies that Caesar existed is equivalent to Caesar was present. Now, I observed, in 2, that sentences involving the past tense express the very same temporal proposition that would earlier have required a present-tense sentence. Thus, most importantly, I do not suppose the

53 Jesse M. Mulder: Defining Original Presentism 51 involvement of a temporal operator, WAS, that takes us to an earlier point on the time line, where we may then find a true (atemporal) proposition Caesar [is] present. That is what we get if we take the tense-logical approach, on which truth is time-relative. On the original view, Caesar was present simply expresses the very same temporal proposition Caesar himself could have formulated by saying Caesar is present. That makes clear both that there cannot be different properties of being present associated with different times, and that the one unique property of being present cannot be rigidly tied to the present moment. 38 On the original view, we simply have truths exemplifying the temporal form of predication. These are basic; their temporality lies in their form, not in their being tied to an assumed time line. As in the case of proposed definition P, we find, with regard to EP, that the same form of words can be used by a presentist to present his view, and by an eternalist to say something fundamentally different. That is because the difference lies in the form of predication used. A statement always involves some form of predication, and therefore there is no neutral, common ground on which a defining statement can be formulated. Tallant s proposal is a move in the right direction; on my reading, it highlights a feature of the original view. But we can be more explicit. So, here is my proposal: OP Temporal propositions display the temporal form of predication. OP says that temporal propositions instantiate the temporal form of predication on which the original view rests, and thus I call a presentist that subscribes to OP an original presentist. Original presentism and eternalism disagree on OP: the eternalist has to reject it. That is because the eternalist understands temporal truth in terms of the atemporal form of predication combined, in some way or other, with a time line. And that amounts to an elimination of the temporal form of predication, contradicting OP. 39 It is likely felt that the question still remains: why should we take OP to yield a version of presentism? Why is it not, instead, a novel definition of A-theory, perfectly compatible with a full ontology of things past, present and future, as I quoted Fine saying [18, p.299]? I already gave the short answer to this question above. As I argued, a full ontology of things past, present, and future, in the relevant eternalist sense, requires that we be able to say of any object included in that ontology that it (atemporally) [exists] at some t. If temporal propositions involve the temporal form of predication, we cannot say anything of that kind. Hence OP indeed yields a version of presentism.

54 52 KRITERION Journal of Philosophy, 2016, 30(2): A much longer answer to this question can be developed, based on a proper elaboration of the original view. I can only sketch the relevant considerations very briefly here. I remarked that the original view exhibits a close interconnection between time and causality between tense and aspect, that is. From that interconnection it transpires that objects to which temporal predication applies (that is, substances) are enduring things capable of causal interaction. And endurance, in the end, only makes sense against a presentist background (although, like in the case of A-theory, eternalism-friendly versions of endurantism can be formulated as well, based on the Fregean nexus). 40 As should be clear by now, the original view encompasses more than just presentism. Properly developed, it may yield a comprehensive metaphysics of time, substance, causality, and more. It remains to be seen to what extent the original temporal nexus can indeed serve as a viable basis for such a comprehensive metaphysics. For all I have argued here, it may still turn out that we do best to discard it. But I hope to have made a case for the claim that the future of presentism depends on it. Notes 1 I will largely restrict myself to the presentist s attitude towards the past here, since the future invites problems of its own, concerning its being or not being open, determinate, or determined, that are not essential to my argument. Moreover, I ignore abstract objects, which, for most presentists, would exist despite arguably not being present in any interesting sense. 2 Hence, I differ from McTaggart s original definition, in terms of properties like being future, being present, and being past, which are thought to be had by times (making up the so-called A-series) [27, esp. p.458]. My reasons for differing in this way will become apparent later on. 3 Interesting examples of eternalist A-theories can be found in Kit Fine [18]. I briefly look into those in 3 below. Arguably, there is room for a B-theoretic version of presentism that claims that there is, fundamentally, only one moment the present and thus only one B-relation: simultaneity. Such a version would presumably not find many defenders. As we will see below, it is identical with the view I call negative presentism. 4 The challenge Meyer develops appears to have found its first serious expression in a discussion between Crisp and Ludlow in Oxford Studies in Metaphysics, vol. 1 see [11, 12, 25]. 5 The very same phrasing of the presentist thesis can be found in, e.g., [9, p.35]. 6 And, we may add, reading the is in P2 temporally general as well again leads to a triviality. In what follows, I will phrase the dilemma that the presentist faces as one of having to choose between a triviality and an absurdity (so that the view is either trivial or untenable). In the discussion, the dilemma is often

55 Jesse M. Mulder: Defining Original Presentism 53 phrased as a choice between a reading that is trivially true and one that is trivially false. Although it is a minor point, I think that is a mistake: while P1, for instance, arguably expresses a tautology, and is thus trivially true, P2 is not a contradiction it s just an absurd claim to make. 7 Crisps definition reads: Pr b For every x, x is a present thing [11, p.18]. 8 Crisp is thus gesturing towards a tensed model theory for his temporal quantifiers. 9 Tallant discusses more proposed definitions than the ones I here present; for instance those by Sider, who tries to establish inferential differences between the presentist and the eternalist quantifiers [37], and by Stoneham, who thinks a difference in the attitude towards truthmaker principles can be established [38]. And still others can be added. Though interesting in their own right, my selection provides me with enough materials to make my point. 10 As Tallant also notes, the same definition has been proposed by Zimmerman, who writes that to be present just is to be real or to exist [45, p.117]. 11 Tallant thinks that Merricks s (and Zimmerman s) formulation is flawed because we can still apply a Meyer-style objection. If existing at the present time just is existing, we can read the just is either as present-tensed or as temporally general: the first reading, says Tallant, is then trivial, the second absurd. But the first reading is not trivial: Tallant confuses the non-trivial (1) existing at the present time just-is-now existing with the trivial (2) existing at the present time just-is existing now. This observation doesn t affect Tallant s proposal, however, because (1) is plausibly a statement of that very proposal. 12 Tallant goes on to consider how one might understand the identity claim EP: it can be read as the identification of the properties of existence and presence but, of course, there are those who don t accept existence as a property. Thus, an alternative is to read it as identifying the ontological category of existence with that of presence. For reasons of scope, I ignore such considerations concerning the wider debate on existence in the present paper. 13 Notice that Tallant thereby in effect rejects the very idea of times as locations, central to the eternalist picture. That will turn out to be a crucial ingredient in my own proposal as well; see 4 below. 14 As I noticed at the beginning of this paper, I conceive of A-theory broadly, so as to be compatible with eternalism. 15 Notice that these two statements have a different form on the usual understanding of that term (namely, Rxy and Rxyz, respectively), but not on my understanding. I say that it is a difference in content because it is just a matter of putting together different ingredients with the help of the Fregean form of predication. Of course, adding an argument place to a given predicate invites the familiar question whether that doesn t amount to changing the topic but that is not my concern here. 16 The index may be built into the content of temporal propositions in different ways, depending on one s preferred views on the matter e.g., as an index to the object(s) in question specifying the relevant temporal part(s), yielding perdurantism, or simply as an argument place for the predicate, yielding a form of endurantism. 17 This is called the imperfective paradox in linguistics [17]. In action theory, attention was drawn to the progressive by Anscombe [1], and, more recently, by Rödl [35, chpt.2] and Thompson [40, chpt.7 8]. Notice, by the way, that no

56 54 KRITERION Journal of Philosophy, 2016, 30(2): interesting differentiation in tense applies to T5: the past perfect tense (e.g., The cat had jumped to the ground ) expresses the same completeness of a process that the present perfect expresses. It does serve further, pragmatic functions but that is not relevant for my purposes. In other languages (such as Russian, with its lexical duplication of each verb into a progressive and a perfective one) aspect and tense are in this respect somewhat more cleanly separated. 18 For simplicity, I do not discuss T6 in much detail, nor its further generalization to the generic Cats jump that would get us into complex considerations concerning the nature of cats (and concerning natures generally but see [31]). And, to repeat, for similar reasons I eschew discussing the future tense. For a much more elaborate investigation into tense, aspect and the time-general as interrelated characteristics of the temporal form of predication, see, respectively, chapters 4, 5 and 6 of Rödl s [34]. 19 Does this mean that that very same temporal proposition is an atemporal B- fact? No: that only follows if one insists that there must be a presentation of that proposition that is independent of its expression using tensed sentences. See also note Similar, but slightly different, observations apply to the aspectual differentiation displayed by T3 T5. In particular, while one is saying different things by uttering T1 at subsequent times, the same doesn t hold for T3: there, the very same statement remains true for as long as the cat jumps (in other words, processes, like substances, endure). Such observations are, however, not central to my aim in this paper. 21 My insistence on tense as a feature of the form of predication might be thought similar to the multiple instantiation tie approach to presentism developed by McKinnon and Bigelow [26]. They write: it is curious that this thought that pastness and futurity are to be located in instantiation has been neglected by presentists. But the peculiarity of temporal predication I just noticed, concerning the way in which past- and present-tensed statements relate, sets my approach apart from theirs. And the same holds with regard to the tensed quantifier approach explored by Baron [8] as a way of dealing with truthmaker issues. Thanks to an anonymous referee for pointing out these relations to me. 22 There are good reasons for choosing the Aristotelian term substance here: Aristotelian substances are what remains constant through change, and that is precisely the role that the temporal form of predication has them play. For present purposes, however, I do not need to defend this claim here, I simply need a term different from object, to flag the distinction from Frege s Gegenstand category. 23 Like the categories of substance and potentiality, others from our list can be associated with certain notions central to Aristotle s metaphysical thought: in particular, the category of feature/relation corresponds to stasis, while process corresponds to kinesis. 24 Given this broad scope, I can only sketch the rough outline of this logical framework in the present paper, geared towards my topic: the definition of presentism. 25 Fine calls this tense-theoretic realism or just realism. For clarity, I here stick to the label A-theory instead of realism. 26 Fine argues that fragmentalism is to be preferred, because it promises to make more sense from the point of view of relativity theory it allows, for instance, for overlapping fragments.

57 Jesse M. Mulder: Defining Original Presentism Nor does it help to resort to tense-logical meta-propositions about the truth or falsity of tense-logical formulae: the present truth of Pp will be true remains unconnected to the present truth, one day later, of Pp is true. The problem lies in the time-relativity of truth. 28 As Wittgenstein notes in Zettel 693 [43], the problem of an infinite regress is not so much its infinity but rather its disabling any understanding of its members in this case, any understanding of cross-temporal fact-sameness. See also [35, p.25]. 29 This sentence comes from an anonymous referee, whom I thank for pointing out the need to clarify this. 30 Thus, it doesn t matter for the point I am raising to which grade of tense-logical involvement one is willing to subscribe [32, chpt.xi] all of them are, after all, grades of tense-logical involvement. One can see this from what Prior writes, towards the end of his explorations of these grades, about the vacuity that It is now the case that has in ordinary tense logic; it does not need to be expressed, but is understood in all that we say. (p.134, my emphasis). If it is really understood in all that we say, we are indeed forever banned within what is now the case within what is-present-true. Prior s translation project in the mentioned paper succeeds insofar as it enables one to translate everything one can say using the earlier-later calculus using only tense-logical propositions, the truth or falsity of which is relative to the present moment. The success of that project, however, does not address our worry. 31 This is the one non-a-theoretic version of presentism I mentioned in note 3 above. 32 This time-absolute understanding of temporal truth is criticized by Cord Friebe [22, I.A.2.1], who follows Mellor [28, p.30] in concluding from a temporal truth being time-absolute that that truth has to be a B-theoretic truth. That, however, merely shows how entrenched the assimilation of temporal predication to Prior s tense logic has become: if truth is not time-relative, then only B-theory remains. And that is a non sequitur. 33 In case one wants to hold onto A-theory in the way Fine does, there will be no such propositions, as it is denied that there are any propositions whose truth is time-independent. However, we saw that in that case, there still is, for any temporally existing thing x, the proposition x [exists], which is true relative to some t. 34 Does this mean that that very same temporal proposition is an atemporal B- fact? No: that only follows if one insists that there must be a presentation of that proposition that is independent of its expression using tensed sentences. See also note In fact, the formal mismatch goes even deeper. In the case of Fregean propositions, one can safely abstract from the fact that judgments, thoughts, utterances etc. are made in time. While, as can be seen from my exposition of the original temporal nexus in 2, that is not so easy in the case of temporal propositions bearing the form captured in the ogirinal temporal nexus. That is the reason why Rödl, to whose work I owe my approach to the presentism issue, gave his book the subtitle An Inquiry into the Forms of the Finite Intellect [34]. That is also the reason, I should add, why I refrain from proposing any serious formalization of the claims I use for explicating the original temporal nexus and the version of presentism it yields (see below). It is the downside of the habit of supplying formal renderings in analytical philosophy that these are always derived from

58 56 KRITERION Journal of Philosophy, 2016, 30(2): the Fregean nexus as my critical discussion of tense logic in the previous section illustrates. Perhaps a radically different formalism can be developed for the original temporal nexus but I would not know how. 36 Similarly, Crisp s definition of presentism is acceptable to a defender of the original view, though equally trivial. Moreover, Crisp s tensed reading of the domain of temporal quantification, which he uses in his attempt to rebut counterexamples that rely on past objects, can be understood to be in line with the original view. On such a reading, the domain of temporal quantification changes over time: it used to contain Julius Caesar, but doesn t do so anymore. As long as we understand tense, as it figures in this view of quantification, in terms of the original temporal nexus (and not, say, in terms of Priorian tense logic), all of this is perfectly fine. 37 This is analogous to Aristotle s famous remark explicating what existence is for living things: to exist, for a living thing, is to live see [2, p.27; II.5, 415b12 14]. 38 I speak, here, of the property of being present, following Tallant, whose claim EP is after all to be understood as an identification of properties. I do not think this ultimately makes sense; I am more inclined to accept Tallant s alternative rendering of his proposal in terms of the identification of the ontological category of existence with that of presence [39, 3.3]. However, I would then urge for an understanding of ontological categories based on my notion of forms of predication, in which case there would be room for more than one notion of existence. However, I cannot develop the details of such a proposal here. 39 A pessimistic thought may come to mind at this point: the eternalist may simply disagree on the question whether or not there is something to be eliminated here at all. He may claim that there is no such thing as the original temporal nexus, that there is only tense, aspect, and the like in the sense in which they fit his theory (however that may be). If so, I don t think there s much more to say: like Quine s denial of modal talk (of sufficiently robust grades), such a denial of the temporal nexus is just that: an outright denial of a fundamental element of our understanding of reality. 40 For a detailed investigation into the temporal form of predication, see [34] as I said earlier, I owe my approach to the presentism issue largely to Rödl s work. Jesse M. Mulder Utrecht University Janskerkhof 13, 3512BL Utrecht, The Netherlands <j.m.mulder@uu.nl> <

59 Jesse M. Mulder: Defining Original Presentism 57 References [1] G. E. M. Anscombe. Intention. Cambridge, Mass.: Harvard University Press, [2] Aristotle. On the Soul. Princeton: Princeton University Press, [3] Jamin Asay and Sam Baron. The Hard Road to Presentism. In: Pacific Philosophical Quarterly 95.3 (2014), pp [4] Alex Baia. Presentism and the Grounding of Truth. In: Philosophical Studies (2012), pp [5] Mark Balaguer. Anti-Metaphysicalism, Necessity, and Temporal Ontology. In: Philosophy and Phenomenological Research 89.1 (2014), pp [6] Sam Baron. Presentism and Causation Revisited. In: Philosophical Papers 41.1 (2012), pp [7] Sam Baron. Talking About the Past. In: Erkenntnis 78.3 (2013), pp [8] Sam Baron. Tensed Truthmaker Theory. In: Erkenntnis 80.5 (2015), pp [9] John Bigelow. Presentism and Properties. In: Philosophical Perspectives 10 (1996), pp [10] Ben Caplan and David Sanson. Presentism and Truthmaking. In: Philosophy Compass 6.3 (2011), pp [11] Thomas M. Crisp. On Presentism and Triviality. In: Oxford Studies in Metaphysics, Vol. 1. Ed. by Dean W. Zimmerman. Oxford: Clarendon Press, Chap. 2, pp [12] Thomas M. Crisp. Reply to Ludlow. In: Oxford Studies in Metaphysics, Vol. 1. Ed. by Dean W. Zimmerman. Oxford: Clarendon Press, Chap. 2, pp [13] Rafael De Clerq. Presentism and the Problem of Cross-Time Relations. In: Philosophy and Phenomenological Research 72.2 (2006), pp [14] Dennis Dieks, ed. The Ontology of Spacetime. Amsterdam: Elsevier, 2006.

60 58 KRITERION Journal of Philosophy, 2016, 30(2): [15] Mauro Dorato. Presentism/Eternalism and Endurantism/Perdurantism: Why the Unsubstantiality of the First Debate Implies That of the Second. In: Philosophia Naturalis 49.1 (2012), pp [16] Mauro Dorato. The irrelevance of the presentism/eternalism debate for the ontology of Minkowski spacetime. In: The Ontology of Spacetime. Ed. by Dennis Dieks. Amsterdam: Elsevier, 2006, pp [17] D. Dowty. Toward a Semantic Analysis of Verb Aspect and the English Imperfective Progressive. In: Linguistics and Philosophy 1.1 (1977), pp [18] Kit Fine. Tense and Reality. In: Modality and Tense: Philosophical Papers. Oxford University Press, 2005, pp [19] Marcello Oreste Fiocco. A Defense of Transient Presentism. In: American Philosophical Quarterly 44.3 (2007), pp [20] Gottlob Frege. Funktion und Begriff. In: Funktion, Begriff, Bedeutung. Fünf logische Studien. Ed. by Günther Patzig. Göttingen: Vandenhoeck & Ruprecht, 1891, pp [21] Gottlob Frege. Über Begriff und Gegenstand. In: Vierteljahresschrift für wissenschaftliche Philosophie 16 (1892), pp [22] Cord Friebe. Zeit Wirklichkeit Persistenz: Eine präsentistische Deutung der Raumzeit. Paderborn: mentis, [23] David K. Lewis. On the Plurality of Worlds. Blackwell Publishing, [24] David K. Lewis. Tensing the Copula. In: Mind (2002), pp [25] Peter Ludlow. Presentism, Triviality, and the Varieties of Tensism. In: Oxford Studies in Metaphysics, Vol. 1. Ed. by Dean W. Zimmerman. Oxford: Clarendon Press, Chap. 2, pp [26] Neil McKinnon and John Bigelow. Presentism, and speaking of the dead. In: Philosophical Studies (2012), pp [27] John M. E. McTaggart. The Unreality of Time. In: Mind (1908), pp [28] David H. Mellor. Real Time II. London: Routledge, [29] Trenton Merricks. Truth and Ontology. New York: Oxford University Press, 2007.

61 Jesse M. Mulder: Defining Original Presentism 59 [30] Ulrich Meyer. The Presentist s Dilemma. In: Philosophical Studies (2005), pp [31] Jesse M. Mulder. The Essentialist Inference. In: Australasian Journal of Philosophy 91.4 (2013), pp [32] Arthur N. Prior. Papers on Time and Tense. Oxford: Oxford University Press, [33] Arthur N. Prior and Kit Fine. Worlds, Times and Selves. Amherst: University of Massachusetts Press, [34] Sebastian Rödl. Categories of the Temporal: an Inquiry Into the Forms of the Finite Intellect. Cambridge, Mass.: Harvard University Press, 2012/2005. [35] Sebastian Rödl. Self-Consciousness. Cambridge, Mass.: Harvard University Press, [36] Steven Savitt. Presentism and Eternalism in Perspective. In: The Ontology of Spacetime. Ed. by Dennis Dieks. Amsterdam: Elsevier, 2006, pp [37] Theodore Sider. Quantifiers and Temporal Ontology. In: Mind (2006), pp [38] Tom Stoneham. Time and Truth: The Presentism-Eternalism Debate. In: Philosophy 84.2 (2009), pp [39] Jonathan Charles Tallant. Defining Existence Presentism. In: Erkenntnis 79.3 (2014), pp [40] Michael Thompson. Life and Action. Cambridge, Mass.: Harvard University Press, [41] Giuliano Torrengo. Ostrich Presentism. In: Philosophical Studies (2014), pp [42] Giuliano Torrengo. The Grounding Problem and Presentist Explanations. In: Synthese (2013), pp [43] Ludwig Wittgenstein. Zettel. Ed. by G.E.M. Anscombe and G.H. von Wright. Berkeley and Los Angeles: University of California Press, [44] Dean W. Zimmerman, ed. Oxford Studies in Metaphysics, Vol. 1. Oxford: Clarendon Press, [45] Dean W. Zimmerman. Persistence and Presentism. In: Philosophical Papers 25.2 (1996), pp

62

63 Carnap s Logic of Science and Reference to the Present Moment Florian Fischer Abstract The important switch from the so-called old B-theory to the new tenseless theory of time (NTT), which had significant implications for the field of tense and indexicals, occurred after Carnap s era. Against this new background, Carnap s original inter-translatability thesis can no longer be upheld. The most natural way out would be to modify Carnap s position according to the NTT; but this is not compatible with Carnap s metaphysical neutrality thesis. Even worse, Carnap s work on measurement theory can be used to develop an argument in favour of the A-theory. I argue that there are tensed basic sentences which are needed in order to construct a tenseless system and thus cannot be translated without loss of meaning into tenseless ones (old B-theory) or made true by tenseless facts (NTT). Keywords: Rudolf Carnap, Philosophy of Time, Tense vs. Tenseless Theory, A-Theory, B-Theory, New Tenseless Theory of Time 1 Carnap and Tense This paper brings the work of Rudolf Carnap together with the modern debate about tense in the philosophy of time. It is an interesting fact that these fields have never been put together, 1 despite the fact, or so I believe, that their content is deeply connected. The debate between so-called tensed and tenseless theories is a central issue in contemporary philosophy of time. Tensers hold that grammatical tense is semantically irreducible, while detensers hold that tense is semantically reducible [69, p. 2]. Under the buzz phrase tensed versus tenseless theory, I subsume different philosophical positions about the reference to the present moment. This divide places tensed theory, A-theory and indexicality on one side, and tenseless theory, B-theory 2 and non-indexicality on the Kriterion Journal of Philosophy, 2016, 30(2): c 2016 The author

64 62 KRITERION Journal of Philosophy, 2016, 30(2): other. I will go into the details of some of the positions later; for now, it suffices simply to set out the broad division into two camps. The tensers 3 believe that the (firstly linguistic) reference to the present is meaning-constitutive. This reference can be encoded in the tense or aspect 4 of a sentence or expressed by an indexical like now or tomorrow. The detensers want to get rid of this reference to the present, be it by translation (old B-theory) or by giving tenseless truth conditions (new tenseless theory of time, or NTT for short). A quick glance at the chronology of publication shows that the relevant philosophical work by Carnap took place significantly earlier than the switch from the old B-theory to the NTT. In 1926 Carnap published his Physikalische Begriffsbildung [16]. His Aufbau [12] is from 1928, and his considerations about protocol sentences are from 1932 [25]. In 1934, he published his main work in pure syntax [22], while by 1942 his semantic turn had taken place [15]. Prior s Thank Goodness argument [60] was published in 1959, only four years before Carnap s intellectual autobiography [14] and 20 years before Perry s Essential Indexicals [58]. Mellor s Real Time [49] was not published until 1981, and his Real Time II appeared as recently as 1998 [50]. A re-evaluation of Carnap s work in this new light is important for at least two reasons: (a) Carnap s position reveals the costs of the NTT. Not all of the old B-theoreticians can easily convert to the NTT, for the NTT is much too metaphysical for the likes of Carnap and makes too many concessions to the A-theory in accepting the impossibility of translation without loss of meaning. (b) The newer debate in the philosophy of time makes us aware of the internal tension in Carnap s work. Carnap wanted to be metaphysically neutral, and thus systematically underestimated the implications of his own findings. In various places, for example, he contended that time has a special empirical status (e. g. [13], [24], [16, p. 14] and [27, p. 78]), but never explored the possible philosophical consequences of this Extracting Carnap s stance on tense Before we can evaluate the impact of the newer developments in the philosophy of time for Carnap s position, we have to ascertain the status of indexical concepts for his logic of science. Carnap s early work up to Der logische Aufbau der Welt [12] differed in some important points from ideas he developed in Testability and Meaning [17] or his Philosophical Foundations of Physics [27]. So, the first goal of this paper is to provide

65 Florian Fischer: Tensed Logic of Science 63 a rough reconstruction of Carnap s thoughts on tense. Carnap upheld the inter-translatability thesis throughout his career: This neutral attitude toward the various philosophical forms of language, based on the principle that everyone is free to use the language most suited to his purpose, has remained the same throughout my life [14, p. 18]. Carnap always believed that ultimately one can choose between different languages. 6 The logic of science, for example, can be based on a physicalist or a phenomenalist language, 7 [14, p. 18]. These languages are inter-translatable. This is deeply connected with Carnap s belief in conventionalism, the philosophical position according to which the truth of a certain proposition [... ] is in some sense best explained by appeal to intentional human actions, such as linguistic stipulations [68, p. 169]. Carnap s so-called principle of tolerance was perhaps better called the principle of conventionality [15, p. 247]. For Carnap, it is only considerations of convenience (or pragmatics) that can decide in favour of one language over another [65, p. i]. Within this context, Carnap also dismissed indexicals as unessential. According to standard definitions, an indexical is a linguistic expression whose reference can shift from context to context [9]; alternatively, An indexical expression is one whose extension varies with variation in features of its context of use, but which is otherwise rigid [42, p. 237]. Following Bar-Hillel, I take the term indexicals to include I, now, and here as well as this and that [4]. Carnap believed that indexicals can be replaced by time and date specifications and the like, and that they should be so replaced to arrive at an intersubjective description of the world: for science, it is possible and at the same time necessary to restrict itself to structure statements [21, p. 30]. Another main thesis endorsed by Carnap is metaphysical neutrality. This thesis stems from logical positivism and is closely connected to the empirical sense criterion. To avoid bad metaphysics, Carnap always opted for metaphysical agnosticism. The empiricists/positivists claimed that the only source for our knowledge is the directly given, namely sense-data. Every concept of science should be reduced to the relevant sense data. Carnap s Aufbau [12] from 1928 is a detailed execution of this agenda [75, p. 37]. All scientific statements should be able to be proven wrong (falsified) or right (verified) by reference to sense data. If successful, the Aufbau s program would also show that, besides the positivist s given, no other source of knowledge is needed [12, 5]. The program of the Aufbau is not to be understood as logically necessary. Quite the contrary, it includes a lot of systematic choices. Carnap

66 64 KRITERION Journal of Philosophy, 2016, 30(2): chose the object domain and decided to take an auto-psychological phenomenalist basis [12, 64], which means that, ultimately, the experiences of an individual subject lie at the basis of his constructional system. A constructional system attempts a step-by-step derivation or construction of all concepts from certain fundamental concepts, so that a genealogy of concepts results in which each one has its definite place [21, p. 5]. In Carnap s methodological solipsism, cultural objects are based in other minds, which are themselves based in physical objects, which again themselves are based in phenomenal ones via quasi-analysis, 8 according to their order of epistemic priority. 9 Carnap opted for the intertranslatability [12, p. 57] of the physical and the phenomenological. He believed it to be possible to construct the physical objects via quasianalysis from a phenomenological basis: According to the conception of epistemic priority in the Aufbau, the world of science was recoverable from the resources of individual epistemic subjects alone [75, p. 37]. Intersubjectivity was a main criterion for Carnap s logic of science. He thought that indexicals were incompatible with intersubjectivity and thus devised a method for getting rid of them. [E]ach scientific statement can in principle be so transformed that it is nothing but a structure statement. But this transformation is not only possible, it is imperative. For science wants to speak about what is objective, and whatever does not belong to the structure but to the material (i. e. anything that can be pointed out in a concrete ostensive definition) is, in the final analysis, subjective. One can easily see that physics is almost altogether desubjectivized, since almost all physical concepts have been transformed into purely structural concepts. [21, p. 29] Carnap s Logical Syntax of Language [22] transposed his previous work to the methodological level [43, p. 21]. Carnap did not claim that words do not have a meaning, but he systematically excluded the meaning and hence [n]o reference to the meaning of the signs and expressions is made in logical syntax [47, p. 554]. Carnap also expelled indexicals in this so-called syntactical period, and proposed a translation scheme. The coordinate replacement thesis was the plan to replace name-languages with coordinate languages [21]. The replacement has to take place since the method of designation by proper names is the primitive one; that of positional designation corresponds to a more advanced stage of science and has considerable methodological advantages over the former [14, p.

67 Florian Fischer: Tensed Logic of Science 65 12]. 10 Carnap s method of uniquely designating structural descriptions from the Aufbau [12, sec. 16] is applied in the Logical Syntax of Language in order to eliminate indexicals in favour of non-indexical descriptions. In chapter B of Logical Syntax of Language [22] Carnap is concerned with the syntax of any language. There he completely dismisses indexicals such as now : In case of sentences in which words like I, you, here, now, to-day, yesterday, this (in the sense of the one present ) and so forth occur, the logical character is not only dependent upon the preceding sentences, but also upon the extra-linguistic situation namely, upon the spatiotemporal position of the speaker. In what follows, we shall deal only with languages which contain no expression dependent upon extra-linguistic factors. The logical character of all the sentences of these languages is then invariant in relation to spatio-temporal displacements; two sentences of the same wording will have the same character independently of where, when or by whom they are spoken. In the case of sentences having extra-syntactical dependence, this invariance can be attained by means of the addition of person-, place-, and timedesignations. [22, p. 168]. But as Carnap s major disciple Yehoshua Bar-Hillel remarks, it is quite clear that this qualification restricts highly the applicability of Carnap s general syntax to ordinary languages. The overwhelming majority of the natural language sentences are indexical, i. e. dependent upon extra-linguistic factors [5, p. 524]. Indeed, not long after the publication of Logical Syntax Carnap came to the conclusion that the one-sided restriction to syntax may have been fruitful, but was also very austere: this method studies only the forms of the expressions, not their meanings [22, p. 52]. A calculus can be interpreted and applied to objects and the syntax must thus be complemented with a semantics. Taking semantics into account restricts the conventionalist freedom, however, since possible interpretations have to be considered [43, p. 21]. Carnap did indeed become more interested in the meaning of expressions after this semantic turn, but he did not lift the ban on indexicals. Besides this, Carnap was concerned with time in the context of measurement and with indexicals in the context of the protocol sentence

68 66 KRITERION Journal of Philosophy, 2016, 30(2): debate. Both will be discussed later in the paper. For now we need only observe that Carnap shunned indexicals throughout his career. He either systematically excluded them, or voted for replacing them with allegedly more reputable time-designations. Carnap thus clearly belongs in the camp of the (old) B-theory, believing that tensed sentences can be translated without loss of meaning into tenseless ones. 1.2 Translatability of tensed sentences and the NTT s metaphysical commitment The opposing view, that the meaning of a tenseless sentence differs from the meaning of its tensed counterpart, did have some proponents even in Carnap s time. From within Carnap s close social environment, this position was maintained by Moritz Schlick. The so-called protocol sentences debate within the Vienna Circle revolved exactly around this topic. 11 If I make the confirmation Here now blue, this is not the same as the protocol statement M. S. perceived blue on the nth of April 1934 at such and such a time and such and such a place. The latter statement is a hypothesis and as such always characterised by uncertainty. The latter statement is equivalent to M. S. made... (here time and place are to be given) the confirmation here now blue. And that this assertion is not identical with the confirmation occurring in it is clear. [2, p. 226] Protocol sentences were supposed to be the rock on which knowledge, and especially scientific knowledge, should be built. They had to be objective, intersubjective and free of indexicals, as they ought not to depend on the individual person/scientist. In Über Protokollsätze [19] Carnap thus opted for the supposedly objective approach of date and time indication instead of the indexical now. Schlick, however, argued that these protocol sentences cannot be justified. The sentences that are needed to build a system of knowledge sentences such as M.S. perceived blue on such and such date at such and such time at that location are only hypotheses. They are not the immediately given, the positive of the positivists. The only things which are given, according to Schlick, are expressed in sentences like Here now blue which he calls Konstatierungen (confirmations). Konstatierungen are not apt to build a system of knowledge, as they cannot even be written down: A genuine confirmation cannot be written down, for as soon as I inscribe the

69 Florian Fischer: Tensed Logic of Science 67 demonstratives here, now, they lose their meaning [2, p. 226]. Thus a dilemma arises for the foundations of scientific knowledge. Schlickian confirmations are available but insufficient, whereas Carnapian protocol sentences would be sufficient but are not available. The participants of the Vienna Circle became mired in the debate about the status of the protocol sentences. No agreement could be reached, and the question was put on hold and then never resumed [43, p. 16]. This is a historical fact, not a systematic insight, and the systematic quarrel is still not settled today. It is nonetheless remarkable that Schlick, Carnap s contemporary, had already made the case for irreducible indexicals 12 that are not replaceable by times and dates: Neither can they be replaced by an indication of time and place, for as soon as one attempts to do this, the result, as we saw, is that one unavoidably substitutes for the observation statement a protocol statement which as such has a wholly different nature [2, p. 226]. 13 If Schlick is right, then tensed and tenseless sentences are not on a par. Tensed sentences are not incomplete sentences at all but, quite to the contrary, contain a special form of knowledge (Erkenntnis 14 ) that cannot be incorporated in tenseless sentences. Interestingly, the fatal blow for the old B-theory occurred much later. The old B-theoreticians had held a translatability thesis: All tensed sentences are translatable without loss of meaning into tenseless sentences. Frege had proposed a date indication analysis, stating that the tensed sentence It is raining now actually means, say, It is raining at Thursday 13 May 2014 [36, p. 297] or [35]. Russell opted for a tokenreflexive analysis, according to which the sentence should be translated as It is raining at the time point that is co-temporal with this utterance [66, p. 108]. Prior [60] and Perry [58] famously stated that reference to the present moment is both important for our actions and not translatable without loss of meaning into tenseless concepts and sentences. Today, the irreducibility of tensed sentences and beliefs has been accepted all but universally, 15 and recent defenders of the tenseless view have come to embrace the thesis that tensed sentences cannot be translated by tenseless ones without loss of meaning [56, p. 58]. Prior claimed that reference to the present is relevant for actions and that tensed sentences cannot be translated without loss of meaning. His example is the relief or joy someone feels, when, say, an important test is completed. According to Prior, the decisive factor for feeling the joy is that one believes that the test is now completed. It is not enough,

70 68 KRITERION Journal of Philosophy, 2016, 30(2): say, to believe that the test ends at 2:00 p. m. and that 2:15 p. m. is later than 2:00 p. m., because all that is known before the test is taken but doesn t trigger the joy. One says, e. g. Thank goodness that s over!, and not only is this, when said, quite clear without any date appended, but it says something which it is impossible that any use of a tenseless copula with a date should convey. It certainly doesn t mean the same as, e. g. Thank goodness the date of the conclusion of that thing is Friday, June 15, 1954, even if it be said then. (Nor, for that matter, does it mean Thank goodness the conclusion of that thing is contemporaneous with this utterance. Why should anyone thank goodness for that?) [60] Perry uses a different example to argue for the same conclusion: A tardy professor who desires to attend the department meeting on time, and believes correctly that it begins at noon, sits motionless in his office at that time. Suddenly he begins to move. What explains his action? A change in belief. He believed all along that the department meeting starts at noon; he came to believe, as he would have put it, that it starts now [58, p. 4]. Prior s and Perry s arguments changed the debate radically; afterwards, virtually nobody believed that tensed sentences can be translated into tenseless sentences without loss of meaning. Mellor thus proposed another method instead: he stated that tensed sentences can be given tenseless truth conditions. In his first attempt, published as Real Time [49], Mellor understood the meaning of a tensed sentence as a function from utterances to truth conditions. Due to strong critique 16 he later changed his position. In Real Time II [50] the meaning of a tensed sentence is a function from time points to truth conditions. The new B-theoreticians still call their view tenseless, but this tenselessness now concerns the structure of the world. The problem [... ] is to determine whether this aspect [i. e. being tensed] is a feature of reality that is described or merely a feature of the statement by which it is described. Is reality itself somehow tensed [... ] or is it merely that we describe a tenseless [... ] reality from a tensed [... ] point of view? [34, p. 261] The shift from the old to the new tenseless theory was thus a shift from philosophy of language to metaphysics. 17 Old B-theoreticians

71 Florian Fischer: Tensed Logic of Science 69 claimed that tensed sentences are either incomplete (they need the addition of an explicit time and date, like a 2-place relation needs a second relatum) or are linguistically on a par with tenseless ones (the tense being just a façon de parler). The truthmakers of the sentences did not really play a role. True, the position one took regarding tensed sentences was de facto also often mirrored in the position one held regarding the nature of time, 18 but there did not need to be a systematic link between the two: Presentism and becoming have also been associated with the idea that tensed language does not have tenseless truth conditions. However, this is not a necessary connection [45, p. 326]. It might be controversial, but I think that the NTT wedded language to metaphysics. Nowadays, one can only truly be called a B- theoretician if one holds a tenseless world view. 19 Mellor [50] claims that tenseless facts are not only sufficient as truthmakers for tensed sentences, but necessary. This can be seen as a cost of the NTT 20, since it might deter philosophers of language who shun metaphysics from the NTT. Carnap, for example, systematically excluded semantics during his syntactic period [22], while Otto Neurath in Protokollsätze [53] and Radikaler Physikalismus und wirkliche Welt [54] opted for the dismissal of any reference to the language-external reality and the restriction of philosophical attention to language-internal questions [3, p. 146 et sqq.]. Influenced by Neurath, Carnap (e. g. [25]) focused on coherence inside a language system instead of truth as correspondence with the world [43, p. 16]. 21 Mellor s NTT is not an option for such philosophers, who don t believe in facts (whether they be tensed or tenseless) or who want to be metaphysically neutral. It is thus not available to Carnap, since it is compatible neither with his metaphysical neutrality thesis nor with his inter-translatability thesis. 2 Inter-Carnapian tensions and Carnap s unintended argument for the tensed theory As we have seen, Carnap s inter-translatability thesis cannot be held in the universal form. The old B-theory and with it the hope of translatability without loss of meaning between tensed and tenseless sentences had been abandoned after Prior s and Perry s famous arguments. It is, however, also not possible to transfer Carnap s work to the NTT, which is the successor theory to the old B-theory. The NTT may be on the tenseless side of the divide but its specific metaphysical character contradicts Carnap s much-beloved metaphysical neutrality thesis. This is

72 70 KRITERION Journal of Philosophy, 2016, 30(2): no surprise, however. In 2.3 I will sketch a transcendental argument in favour of the A-theory, which relies on Carnap s considerations about time measurement (2.1) and Russell s achievements in the field of indexicals (2.2). The argument also reveals tensions within Carnap s work, which help to explain why he and the NTT form such an odd couple. 2.1 Carnap on time measurement Carnap laid down some interesting thoughts about time measurements in Philosophical Foundations of Physics [27], later reprinted as An Introduction to the Philosophy of Science [11]; these thoughts go back to his Physikalische Begriffsbildung [16]. Duration is a quantitative magnitude, more precisely an extensive magnitude. According to Carnap, extensive magnitudes can be measured with the aid of three-rule schemas, consisting of (1) The rule of equality, (2) The rule of additivity, and (3) The unit rule. 22 Three-rule schemas apply to situations in which two things can be combined or joined in some way to produce a new thing, and the value of magnitude M for this new thing will be the sum of the values of M for the two things that were joined [27, p. 77]. Carnap, following Carl Gustav Hempel, insisted that combination refers to a physical operation in this context, which has to be distinguished sharply from arithmetical addition [27, p. 72]. The measurability with a three-rule schema applies to all extensive magnitudes, but time intervals have a special status because of their physical peculiarities: We cannot manipulate time intervals in the way we can manipulate space intervals, or, more accurately, edges of solid bodies representing space intervals. There are no hard edges of time that can be put together to form a straight line [27, p. 78]. Carnap tried to acknowledge the special status of time intervals by the introduction of a conceptual scale. In the context of time measurements he understood in the rule of additivity T (a b) = T (a) + T (b), with T being the temporal length, as a conceptual operator. Both other rules (equality and unit) are grounded in periodic processes, according to Carnap. Carnap distinguished two sorts of periodicity: In the weak sense, a process is periodic simply if it recurs again and again and again [27, p. 80]. The strong sense requires that in addition to being weakly periodic, it is also true that the intervals between successive occurrences of a certain phase are equal [27, p. 80]. Prima facie one would expect that time measurements need strong periodic processes. There is, however, a problem with this requirement, which

73 Florian Fischer: Tensed Logic of Science 71 Carnap had clearly spotted: We cannot know that a process is periodic in the strong sense unless we already have a method for determining equal intervals of time [27, p. 80]. This is a vicious situation: we need the rules of equality and unit to build a system of time measurement, but we need a system of time measurement to establish the rules of equality and unit. Or so it seems. Carnap proposed a solution to this conundrum which is centred on the equivalence of processes. He elucidated process equivalence with the example of the swinging of a certain short pendulum P, which is compared with the swinging of a longer pendulum P. In view of the fact that the periods of the two pendulums are not equal, how do we compare the two? We do it by counting the swings of both pendulums during a longer time interval. [... ] We may observe, however, that the coincidence is not exact. After ten swings of the short pendulum, the long one already started on its seventh swing [27, p. 82]. Note that already started on its seventh swing only makes sense if the two intervals started at the same time. I will come back to this; let us first go through Carnap s resolution of the alleged vicious circle. To handle the case of the not-exact coincidence, Carnap proposed to observe the pendulums for a longer time interval: In this way we can sharpen our comparison as much as we please [27, p. 82]. On this basis he can now specify process equality: If we find that a certain number of periods of process P always match a certain number of periods of process P, we say that the two periodicities are equivalent [27, p. 83]. Process equality alone does not suffice as a solution to the conundrum, however; an empirical fact is also needed, namely that there is one large class of periodic processes that are equivalent to each other in this sense, and that [a]s far as we know, there is only one large class of this kind [27, p. 83]. At this point Carnap s conventionalism kicks in: We cannot say that the pendulum is the right choice as the basis for our time unit and my pulse beat the wrong choice [27, p. 83]. Carnap equipped us with a method for measuring duration without presupposing equal temporal length. This enables us to measure time as a quantitative concept. 2.2 An unlikely ally for the tensed theoreticians: Russell Russell provides a valuable source for our study of tense and indexicality. In 1940 Russell was arguing along the same lines as Carnap. He claimed in Inquiry into Meaning and Truth that indexicals are not needed in any

74 72 KRITERION Journal of Philosophy, 2016, 30(2): part of the description of the world, whether physical or psychological [66, p. 108]. Later, in 1948, Russell explicitly changed his mind and thus objected to Carnap s position. Russell was now concerned with indexicals because of their importance for knowledge and especially scientific knowledge: they are indispensable, he claimed, in stating the basis of empirical knowledge in immediate experience [31, p. 119]. Russell posited the following four characteristics of indexicals in his book Human Knowledge [31, p. 123]: 1. Coordinate replacement Indexicals, as well as strict names, can be progressively replaced by coordinate descriptions, but only up to a certain point. 2. Indispensability Indexical expressions cannot be entirely eliminated. They are indispensable to human discourse, including any science that requires human observation. 3. Interdefinability Each indexical expression can be defined in terms of another (or a combination of others). 4. Reducibility All indexical expressions can be reduced to one basic type, although this basic type need not be one in particular. Scientific concepts must ultimately terminate in ostensive definitions, according to Russell, and thus indexicals are not completely eliminable [31, p. 119]. Russell s coordinate replacement thesis for indexicals goes back to Carnap s Logical Syntax of Language [22]. Contrary to Carnap, however, Russell thought that this program works only up to a certain point: We cannot wholly dispense with proper names [indexicals] by means of coordinates. 23 Farrell-Smith is very explicit about the limitations that Russell imposes on the coordinate replacement thesis: Coordinates describe a point in space-time. They locate it by means of reference to axes and distance from the origin of axes. But, Russell asks, how do we designate the axes and the origin? We cannot go on indefinitely giving a description of the origin of each system in terms of another system. Ultimately we must be able to say, This is the origin. In other words, we must be able to name the origin, in contrast to merely describing it. [31, p. 119] We can apply Russell s findings on space straightforwardly to the case of time. We need a way of referring to the point of origin outside of

75 Florian Fischer: Tensed Logic of Science 73 the time and date system. Only then can such a system be established. Without it, the term point in time is meaningless: if we do not have a way of knowing some places otherwise than by latitude and longitude, latitude and longitude become unmeaning [67, p. 77]. Unless the whole system should become free-floating, we must have some method of identifying a place [a time] without mentioning the coordinates [67, p. 78]. Then, since the assignment of coordinates requires assigning an origin and axes, the question arises as to whether the origin can be defined. [Russell] answers that it must be defined by reference to something observable. Theoretical constructs like the sun obviously will not do. [31, p. 119] The limitations this introduces to the time case are pretty obvious. Theoretical constructs like the Big Bang cannot serve as the origin; rather, we need something directly observable. [U]nless we already have some non-descriptive way of fixing this framework, i. e. some way of naming its origin, we face a regress that detaches scientific knowledge from its empirical basis [31, p. 119]. 2.3 The argument in favour of the A-theory We have seen that Carnap s original inter-translatability thesis had to be dropped due to the developments in the philosophy of tense. Section 1.2 argued that Carnap can also not be on the side of the NTT, the successor theory of the old B-theory. A tension seems to arise, since some of Carnap s statements clearly place him on the tenseless/b-theoretic side of the divide, as we have seen in 1.1. A closer inspection will reveal that the incompatibility of Carnap s position with the B-theory is not surprising. 24 In his considerations about time measurement, Carnap emphasised that the term longer does not have a meaning without the complete three-rule schema: We do not know what you mean by longer. We are trying to lay down rules for the measurement of time so that we will be able to give meaning to the term longer [27, p. 81]. Parallel to this, I will argue that time and date indications do not have a meaning without a tensed anchor point. If the argument goes through, it will show that the tensed and tenseless approaches are not on a par. The asymmetry towards the tensed is not in line with Carnap s inter-translatability theses, but it fits well with what he says in various

76 74 KRITERION Journal of Philosophy, 2016, 30(2): other places (e. g. [13], [24], [16, p. 14] and [27, p. 78]) where he defends a special status for time. Thus, it would hint at the inner tension within Carnap s work. This tension cannot be dissolved by identifying different periods in Carnap s work. Carnap first developed his thoughts about time measurement in a small volume called Physikalische Begriffsbildung [16] from 1926, a full forty years before Philosophical Foundations of Physics [27]. It is thus safe to say that he held these views throughout his career. I will first go through the premisses, then I will sketch 25 the argument and comment on it. (Presup.): I restrict the argument to the debate between A- and B-theory, a restriction which might be questioned. If the argument goes through it would help the A-theorists a good deal as it does not rely on the experience of time, which is as often consulted as an aid for the A-theory as it is problematic [39]. (Carnap 1): Carnap thought that in the case of sentences having extra-syntactical dependence, [... ] invariance can be attained by means of the addition of person-, place-, and time-designations [22, p. 168]. He thus believed that the indexical now can easily be replaced by a B-theoretic time-designation and should be replaced. (Carnap 2): Carnap emphasised the difference between time and space, as We have two separate events, each with a certain length of time, but there is no way to bring them together. [... ] we cannot shift events around as we can shift the edges of physical objects [27, p. 78]. Time plays a special role for Carnap. (Carnap 3): Carnap showed how to reach a definition of duration via the one large class of periodic processes that are equivalent to each other [27, p. 83]. This premise has the form of an implication. If an origin is supplied, Carnap s specification of duration can be used to build a B-theoretic system of times. (Russell 1): Russell claimed that [w]e cannot wholly dispense with proper names [indexicals] [67, p. 78]. Russell thought that indexicals were interdefinable. Given some (suitable) indexical basis we can define the remaining indexicals. This is a systematic point for Russell, i. e. he doesn t claim that there is one particular indexical which is the objective

77 Florian Fischer: Tensed Logic of Science 75 basis: Russell s claim can rather be understood the other way around, namely that we can never completely leave the realm of the indexical. (Russell 2): Russell argued that we cannot go on indefinitely giving a description of the origin of each system in terms of another system. Ultimately we must be able to say, This is the origin [31, p. 119]. (B-theory): A B-theoretic time specification consists of a time and date indication. (Systematicity): A time and date specification only makes sense within a given system of time. For example It rained at three o clock on the 7th of April only makes sense in respect to a calendaric system, like ours. (Argument - short): The shortest way to set up the argument in favour of the tensed/a-theory side of the divide is to take (Carnap 2) and (Russell 1) and conclude that now is the basic indexical. This is the shortest but arguably also the most uncertain form of the argument. (Russell 1) clearly states that we cannot wholly dispose of indexicals. It is unclear however if (Carnap 2) is really enough to establish that time is fundamental in the sense required. If time is fundamental and we cannot wholly dispense of indexicals, then now has to be the basic indexical. 26 The argument is valid but maybe not sound, i. e. some of the premises may be false. The premise (Carnap 2) is its potential weak spot. Acknowledging a special role for time is not enough; rather, the fundamentality of time must be established. If this short argument goes through it can easily be extended to contradict (Carnap 1). Since now is the basic indexical it is thus not dispensible; but this is exactly the opposite of what (Carnap 1) claims. Note that Russell s considerations from Human Knowledge are not sufficient to set up the argument, since Russell did not believe in any priority among the indexicals. A longer version (Argument - long): (Russell 2) states that each system needs an external anchor. As an instance of that, a system of time needs an external anchor. Now this anchor can either be specified indexically/a-theoretically or non-indexically/b-theoretically. A B-theoretic specification consists of a time indication (B-theory), but this in turn only makes sense within a given system of time (Systematicity). So, on pain of circularity, the origin of a system of time cannot be specified B-theoretically. It thus has to be specified A-theoretically.

78 76 KRITERION Journal of Philosophy, 2016, 30(2): The heart of (Argument - long) is that a system of time cannot be specified by a date and time indication on pain of circularity. A time and date indication only makes sense in reference to an existing system of time and thus cannot be used to build a system of time. Of course, a pre-existing system of time could be used to build up another system of time. I could, for example, use the calendar system of the ancient Greeks with the original Olympic Games as the origin, to specify our calendar system with the birth of Christ as the origin. 27 But ultimately one has to come to an external anchor, and this is what (Russell 2) states. As this is a systematic point, not a mere contingency, it justifies the modal claim that a system of time cannot be specified by a time and date indication (ultimately). This modal strength then justifies the claim that the origin (ultimately) has to be given in indexical terms. As we are talking about a system of time, the indexical in question is now, i. e. the A-theoretic way of specifying the origin. This argument can easily be extended to contradict (Carnap 1). As a system of time needs an indexical anchor, we cannot completely dispose of indexicals (if we want to set up a system of time at all, that is). But there is also a constructive part. Carnap s construction of duration via equivalent processes may help us to build an intersubjective system of temporal location, once we have amended it with a tensed A-theoretic origin. This actually is Carnapian in spirit. In his example from Philosophical Foundations of Physics [27, p. 82], the scientist starts both pendulums in his present and thus both processes start at the same time. To sum up, the construction of any time and date system requires an anchor point, prior (constructively prior, not temporally prior) to this system. This anchor can only be understood as tensed, or so I have argued. If the argument goes through then tensed and tenseless theories of time are not on a par. Granted, one could still choose between the different tenseless theories by convenience, but a tensed anchor is mandatory for there to be a system of time at all. 28 Any system of time order, be it metrical or topological, needs to be pinned to reality, so to speak, in order to have empirical content. 29 With tolerance in place, Carnap is prepared to imagine non-empiricist languages, though of course he thinks they are very unwise [30]. Thus Carnap also has to deem a purely tenseless system of time, without an tensed anchor, very unwise. The argument is not only about statements occurring in scientific theories, but about the prerequisites for establishing any B-theoretic

79 Florian Fischer: Tensed Logic of Science 77 time order. This may not be on Carnap s agenda, but still, I think, it is rooted in his systematic thoughts about time measurement. Carnap s early characterisation of a time topology might include a short cut to the result that A-theoretic simultaneity is a precondition of a B-theoretic time order, 30 as Carnap explicitly bases physical simultaneity on local phenomenological simultaneity. In Physikalische Begriffsbildung [16, p. 37], Carnap defined simultaneity (i. e. when two events get the same value of time) in the following way: Two events are physically simultaneous if they are perceived together. There Carnap explicitly states that physics presupposes phenomenological simultaneity as a determinable basic relation [16, p. 38]. Be that as it may, right now I am concerned with a more general point. Every B-theoretic system of time order, be it a topology or a metric, needs an anchor outside the system in order to be built in the first place. To arrive at a numeric value for a (B-theoretic) time and date indication, we need to fix an initial point and an ongoing process to specify the time-wise distance to this initial point. Carnap himself writes: We don t know of an initial point of the time series. An arbitrarily chosen time point has to be fixed as the point of origin of the time scale, as it is done in the various calendar systems (first year; first day of the year). 31 The origin thus cannot be specified by a time and date indication, since it is needed to set up a calendar system in the first place. In order to be able to order events in a calender system, people at some point needed to say we start counting years now, this is year one. The earlier/later relation is dependent on the A-series of past/now/future, and thus tensed sentences can neither be translated without loss of meaning into tenseless ones nor can they be given tenseless truth conditions. The argument I have sketched does in no way question the usefulness of a tenseless system of times and dates; it seeks only to show that a B-theoretic time and date indication is meaningless without an A-theoretic anchor, just as the term longer is meaningless without a system of time measurement. Carnap and Russell were concerned chiefly with epistemological questions, but the argument can also be given a more metaphysical 32 gloss: [T]he philosophy of A-time or B-time, perhaps more than any other area, has shown the continuing relevance of the idea that natural language is, in some carefully qualified sense, a guide to the nature of reality [41, p. 4]. After all, it was the tenseless theoreticians who strengthened the link between language and ontology by adhering to the NTT, so now

80 78 KRITERION Journal of Philosophy, 2016, 30(2): they have to face the music: Our system of knowledge is rooted in irreducible tensed sentences, from which tenseless date and time indications can be derived. This is not a choice of convenience but something that is necessitated by the requirements of construction. If our knowledge has something to do with the structure of the empirical world, how could there be only tenseless facts in the empirical world? To clarify where the onus of proof falls: The tenseless theoretician acknowledges the irreducibility (i. e. the non-translatability and indispensability) of tensed sentences but thinks she can still dispense with tensed facts by positing tenseless facts as truthmakers. The existence of tenseless facts is a heavyweight ontological claim, according to Chalmers s categorisation in [28]. The B-theoreticians acknowledged the necessity of tensed beliefs for our actions. If now the existence of a system of tenseless earlier/later depends on the A-series of past/present/future, as I have tried to show, then the odds for tenseless facts as truthmakers for empirical sentences are bad. 33 However, this is not to deny the utility of a tenseless system of times and dates. Carnap made an important contribution on how to construct such a system, namely by using periodic processes and, most conveniently, the class of equivalent processes. 3 Concluding remarks This paper focused on the interrelations between the modern philosophy of time and Carnap s work. Carnap held an inter-translatability thesis throughout his career. He believed that, ultimately, one can choose between different languages, because one can translate sentences between different languages, such as the physicalist s or the phenomenalist s language, without loss of meaning. This includes the translation of indexicals into time, date and name indications without loss of meaning. Exactly the same translatability of tensed sentences into tenseless counterparts was adhered to by the old B-theoreticians. Nowadays, the old B-theory has been given up for good. After Prior s and Perry s famous arguments, virtually no one now champions the old B-theory. Carnap s inter-translatability thesis can no longer be upheld. The NTT, founded by Mellor, is the centerpiece of modern tenseless theories: but Carnap cannot stomach the NTT, since it is too metaphysical for him. According to Mellor, tenseless facts and only tenseless facts are apt truthmakers for tensed sentences. This contradicts Carnap s metaphysical neutrality thesis. It is no surprise that Carnap and the NTT do not fit well together. To

81 Florian Fischer: Tensed Logic of Science 79 show this, I have tried to extract an argument against the tenseless theory out of Carnap s own remarks concerning time measurement. Carnap devised a clever way to measure duration as a metrical property, without succumbing to the lurking vicious circle. To build a system of times and dates, an origin must also be specified. Any B-theory requires such a system of time: the old B-theory on the level of language, and the NTT on the level of truth-makers. On pain of circularity, the origin cannot be specified B-theoretically and thus must be specified A-theoretically. This is backed up by Russell, one of the most prominent old-b-theoreticians, who claimed that indexical expressions cannot entirely be eliminated. A tenseless system of time and date indications requires a tensed anchor point to have empirical content. This not only shows that Carnap s ideas do not fit well with the NTT, but also that there are pre-existing tensions within Carnap s work. On the one hand Carnap wanted to get rid of all indexicals in his quest for intersubjectivity; on the other hand he was well aware that [w]e cannot manipulate time intervals in the way we can manipulate space intervals [27, p. 78]. Acknowledgements Parts of this paper were written during a research stay in Oxford financed by the DAAD. I m very grateful for their support. Earlier versions of this paper were presented at the Interchair Colloquium in Bonn in 2014, the Tensed vs Tenseless Theory symposium ( at the SOPhiA conference in Salzburg 2014, and the Being in Time conference ( in Bonn I would like to thank the audiences there for enjoyable and fruitful discussions. I would also like to thank Thomas Müller and his group in Konstanz, to whom I presented the paper in I have benefited a great deal from the SPoT discussion groups ( in Bonn, and in particular I am deeply grateful to Sonja Deppe, Cord Friebe, Johannes Größl and Thorben Petersen. Maren Bräutigam, Toby Friend, Caro Haupt, Stefan Heidl, Ludger Jansen, Martin Pickup, Matthias Rolffs and Niko Strobach all helped to improve the paper, and I am very grateful to them all.

82 80 KRITERION Journal of Philosophy, 2016, 30(2): Notes 1 I know of one paper which contains the words Carnap as well as tense, but it has nothing to do with our topic: Arthur Prior s example just happens to be Professor Carnap will fly to the moon [59, p. 268]. In addition, Arthur Pap [57] speaks of tense versus tenseless in the context of Carnap s Testability and Meaning [17] but he conflates tense with time: tensed, and hence time-referent form [57, p. 565]. As will become clear later, in the debate in the philosophy of time both sides agree that there is some kind of time reference; they disagree, however, about whether this essentially involves a reference to the present (tensed theory) or not (tenseless theory). 2 The old B-theory says that tensed/indexical sentences are tenseless/nonindexical sentences in disguise, and hence that tensed sentences have tenseless truth conditions. The new B-theory denies that tensed/indexical sentences are tenseless/non-indexical sentences in disguise, but agrees that tensed sentences have tenseless truth conditions [69, p. 11]. 3 According to Peter Ludlow, tensers think that propositions (or in any case bearers of truth) shift in truth-value over time [... ], while detensers put a time index in propositions and argue that propositions are anchored to a time [... ] in such a way that the proportions are eternal [46, p. 691]. As so often happens, in the debate between tensers and detensers the devil lies in the details. Ludlow [46] gives a good overview of the possible positions and their problems. For our purpose it is sufficient to get clear on the broader picture. In using tensed talk, for detensers we are just talking about a series of tenselessly existing events ordered by the earlier-than/later-than relation [46, p. 690], whereas for tensers we are talking about some important temporal feature of the world (for example a tensed fact like the fact that it rained yesterday that currently obtains) [46, p. 690]. I will switch freely between the terms tensed theory, tensers, and A-theory (as well as their counterparts) in this paper; whenever a specific linguistic or ontological reading is meant, I ll make this clear. 4 Many of the features which traditionally have been assigned to tense by linguists now are considered aspectual. Tense and aspect are, to be sure, closely related: both have to do with time, and both are, generally speaking, expressed grammatically by modifications of the verb [40, p. 2 3]. Aspect has long been neglected outside linguistics. Antony Galton remarks that Prior had worked out a tense logic in 1955 [61], the idea of which had already been stated by Findlay in 1941 [33], and yet his own logic of aspect was published as recently as Carnap s discussion with Einstein about the Now may be a good illustration of this attitude. Once Einstein said that the problem of the Now worried him seriously. [... ] But I definitely had the impression that Einstein s thinking on this point involved a lack of distinction between experience and knowledge. Since science in principle can say all that can be said, there is no unanswerable question left [14, pp ]. It seems that Carnap thought that there was just no need to wonder further. 6 This neutral attitude toward the various philosophical forms of language, based on the principle that everyone is free to use the language most suited to his purpose, has remained the same throughout my life. It was formulated as principle of tolerance in Logical Syntax and I still hold it today [14, p. 17]. Carnap s original formulation of the Principle of Tolerance runs as follows: It is not our

83 Florian Fischer: Tensed Logic of Science 81 business to set up prohibitions, but to arrive at conventions [22, p. 51]; or, a bit later in the same book, In logic there are no morals. Everyone is at liberty to build his own logic, i. e. his own form of language, as he wishes [22, p. 52]. This famous principle is not quite the same as the inter-translatability thesis as the latter is a prerequisite of the former. Only if the languages are inter-translatable may we freely choose between them. Note that the other direction doesn t hold: one can think of different languages as inter-translatable and still be an eliminativist. Holger Andreas claims that this is the stance adopted by Carnap in his Aufbau [12]. Carnap s goal was to provide rules for translating sentences containing non-basal concepts into sentences containing only basal concepts. The non-basal concepts are then eliminated in favour of the basal ones [1, p. 43]. 7 According to phenomenalism, physical objects are not themselves given but are reducible to or definable in terms of the occurrence and obtainability of [7] sensory experience. Whereas the thesis physicalism maintains that the physical language is a universal language of science that is to say, that every language of any sub-domain of science can be equipollently translated into the physical language [22, p. 320]. 8 Carnap s (in)famous method of quasi-analysis constructs physical objects from the contents of elementary experiences, which he took to be unanalysable and holistic. [1], [48] and [32]. 9 Here it is important for us to distinguish the metaphysical project from the epistemic, as Carnap wanted to stay metaphysically neutral. This epistemological reading is compatible with Carnap s very strict exclusion of questions of ontology as bad metaphysics: the choice of the basis is a matter of choosing a language [55, p. 2]. 10 Carnap s own example of color nicely elucidates this point. In physics, we apparently have a property description when the color names ( blue, red, etc.) are used. In present-day physics, descriptions of this kind are nothing but abbreviations, since they presuppose wave theory and since the color names can be translated into expressions of this theory (i. e. rates of oscillation). However, formerly, these property descriptions revealed the incomplete character of the theory of light, since they were not transformable into relation descriptions. [21, p. 21]. 11 For an introduction to the protocol sentences debate, see [74, p. LVI]. This volume also features the original papers by Carnap and Schlick in chapter Of course this claim by Schlick is not without its own prehistory. Schlick s work, however, is far less philosophically reprocessed than one would assume, given his status as founder of the Vienna Circle [72, p. 9]. 13 An observation statement is a statement expressing a direct observation. Carnap understood direct observation as perception that is unaided by technical instruments and inferences [27, Ch. 23]. For criticism of this characterisation see [1, ch. 2.1]. 14 Schlick s paper is consequently called Das Fundament der Erkenntnis. [71]. 15 According to Cord Friebe, Sebastian Rödl [64] may be the village of indomitable Gauls with respect to this claim [38, ch. A.2.1]. 16 A discussion of the theory in Mellor s Real Time can be found in [56]. There, advocates as well as enemies of the New Theory of Time have their say.

84 82 KRITERION Journal of Philosophy, 2016, 30(2): I take the old B-theory to be metaphysical neutral, if not anti-metaphysical. The logical empiricists believed that the surface structure of sentences is not identical to their logical deep structure and that thus logical analysis is necessary to unravel the semantics of our messy language (e. g. [62, p. 170]). For example Quine, a champion of the old B-theory, subscribed at least for a time to the empiricists anti-metaphysical program [30]. But people might think differently about the old B-theory. If the the old B-theory, is already a metaphysical view, as, one could argue, with the translatability of tensed into tenseless sentences comes the obligation to also give tenseless truth conditions, then Carnap may not even be compatible with the old B-theory. This however does not undermine my general point that Carnap s views are not only in tension with the B-theory but that arguments for the A-theory can be built upon them. 18 [73, p. xiii] for example speaks of tensed theories of time, in particular presentism which illustrates the entrenchment of this debate. 19 Nathan Oaklander states that [t]ensed discourse is indeed necessary for timely action, but tensed facts are not [56, p. 58]. Oaklander s claim does not amount to an argument for a tenseless theory, however. If the truth conditions of tensed sentences can be expressed in a tenseless metalanguage that describes unchanging temporal relations between and among events [56, p. 58, my emphasis], this only makes a tenseless theory a viable option: without this can, a tenseless theory could not be held after Prior and Perry s famous arguments. Consequently the NTT ler want more and claim that tenseless facts are necessary as truthmakers for tensed sentences. We will not go into this here, but e. g. Mellor s [50] arguments seem to only affect non-pure presentism [29]. If this is the case, then pure presentism might contest the necessity of the tenseless truthmakers. 20 I do not want to claim, that metaphysics is per se a bad thing. To say it with the words of Jiri Benovsky What I aim at here is to provide myself and my reader with tools that enable us to evaluate the cost-benefit ratio of the different views under consideration [6, p. 8]. What may seem as a cost to one person may be seen as a virtue by another. Nevertheless it is important to make the implications of philosophical positions explicit. On top of that I take agnosticism to be a metatheoretical value, i. e. I take a philosophical position that is less committing to be superior. It s a variant of Occam s razor: Do not subscribe to anything, which is not necessary. In this sense the NTT s metaphysical commitment might ceteris paribus be seen as a cost. 21 As a consequence, Carnap concentrated on methods of justification ([26], [23] and [20]) and testability ([17] and [18]) rather than truth in the following. 22 Carnap s complete account of measurement need not concern us here. I will highlight the bits, which are important for our present purpose in due course. The reader, who wants to know more about the three rules or other aspects of Carnap s thoughts on measurement, is referred to Carnap s An Introduction to the Philosophy of Science [11], which is easily accessible. 23 [67, p. 78] Russell uses the term name here, but what he refers to are indexicals. This and that are his prime examples. 24 Well, partly not surprising. On the one hand Carnap really believed that sentences with indexicals can and should be translated into their B-theoretic counterparts. On the other hand, as I will show, there are opposing tendencies in Carnap s work, which can be used to base an argument in favour of the A-theory.

85 Florian Fischer: Tensed Logic of Science 83 These two tendencies towards the A- and towards the B-theory are temporally overlapping and can thus not be explained away trying to identify different phases in Carnap s work. 25 The way I present the argument, it is confined to Carnap s thoughts about measurement. Newer developments in measurement theory may change its systematic premises. I thank an anonymous referee for insisting on this point. This paper seeks to show the systematic impact of newer developments in the philosophy of time on the position that Carnap held, and a similar impact by the newer measurement theory is also plausible. I think that the transcendental argument is independent of this, but I can t show this here. 26 Charlie Dunbar Broad [10, p. 58]), William Lane Craig [29, p. 118] and Thomas Müller [51, p. 206] also come to the conclusion that now is (one of) the basic indexical(s). They state for example that here is derivative of the indexicals now and I, since here actually means where I m now. 27 The two ways of specifying the origin are also distinguished by Nicholas Rescher: The distinction between dates and pseudo-dates points to the existence of two very different chronological dating-procedures, depending upon whether the fundamental reference-point the origin in mathematical terms of the chronological scheme is a chronologically stable date or a chronologically unstable pseudo-date. If the origin is a pseudo-date, say today, we shall have a style of dating all of whose chronological specifiers are pseudo-dates, e. g. tomorrow, day-before yesterday, four days ago, etc. If, on the other hand the origin is a genuine date, say the founding of Rome, or the accession of Alexander, we shall have a style of dating all of whose dates are of the type, e. g two hundred and fifty years ab urbe condita. [63, p. 79] 28 Truls Wyller [78] [76] [77] [79] agrees that localisations like X years before the birth of Christ are only apparently indicator-free [76, p. 74]. He is very explicit about the need for an indexical anchor: The reference to the earthquake in San Francisco is only a help for temporal localisation if I know when the earthquake did take place. This knowledge can t consist of further references to objective circumstances. In order for me to know when a certain event took place, such reference-chains must have an indexical anchor somewhere. [... ] The same thing holds for conventional systems of dates, like the reference to the birth of Christ. This birth can only be used for temporal localisation, as such as it today marks a time point so and so many years ago. (Translation FF. [76, p. 74]. Albeit Wyller uses this in an argument for an different, more radical, conclusion: He argues for transcendental idealism. In transcendental idealism, space and time are held to be nothing but forms of human experience. Accordingly, without the existence, somewhere in the universe, of human beings, there would be no space and time [77, p. 325]. 29 Truls Wyller agrees with this and may even go one step further, since he claims that empirical events are only locations if they are embedded into an indexical frame of reference: Ihren Status als Lokalisationen gewinnen empirische Ereignisse allerdings erst durch ihre Eingliederung in ein indexikalisches Bezugssystem [76, p. 74]. 30 For the identification of B-time with time order, see [37] in this volume. 31 [16, p.40] translation by FF. The German original is: Wir kennen keinen Anfangspunkt der Zeitreihe. Es muß daher ein willkürlich gewählter Zeitpunkt als

86 84 KRITERION Journal of Philosophy, 2016, 30(2): Nullpunkt der Zeitskala festgesetzt werden, wie es in den verschiedenen Kalendersystemen geschieht (Anfangsjahr; Anfangstag des Jahres). 32 The existence of tensed facts is not to be equated with presentism. According to presentism, the present is privileged in the strongest way possible, since only currently existing objects are real [73, p. 11]. Kit Fine however argues that it may be allowed that there are tensed facts (or the like) but denied that the present time is in any way privileged. [34, p. 262], i. e. that there are tensed facts without presentism. 33 I do not claim that all facts are tensed. Perhaps mathematical statements need tenseless facts as truthmakers. I just want to argue that not all tensed sentences can have tenseless truthmakers. Florian Fischer University of Bonn Institut für Philosophie Am Hof Bonn <fischerf@uni-bonn.de> < References [1] Holger Andreas. Carnaps Wissenschaftslogik. Paderborn: Mentis, [2] A. J. Ayer. Logical Positivism. Free Press Paperback. New York: Free Press, [3] A. J. Ayer. The Foundations of Empirical Knowledge. London: Macmillan, [4] Yehoshua Bar-Hillel. Indexical Expressions. In: Mind (1954), pp [5] Yehoshua Bar-Hillel. Remarks on Carnap s Logical Syntax of Language. In: The Philosophy of Rudolf Carnap. Chicago, La Salle: Open Court, 1963, pp [6] Jiri Benovsky. Four-Dimensionalism and Modal Perdurants. In: Topics on General and Formal Ontology. Ed. by Paolo Valore. Polimetrica International Scientific Publisher, 2006, p. 137.

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93 Time Order, Time Direction, and the Presentist s View on Spacetime Cord Friebe Abstract The physical possibility of spacetimes containing closed timelike curves (CTCs) challenges the philosophy of time in the way that temporal ordering is, at best, remarkably non-standard: events on CTCs precede themselves. Apparently, such universes do not possess a consistent time order but only a consistent time direction. Thus, temporal directionality seems to be more fundamental than ordering in earlier-later or past-present-future. I will argue that this favors presentism as the adequate ontology of spacetimes: only presentism consistently copes with the idea that temporal ordering depends on empirical constraints. The presentist Now is fundamentally undivided and productively directed towards existence. Time order arises by extending the Now, which can fail and in fact fails in universes containing CTCs. Keywords: general relativity, philosophy of time, presentism 1 Introduction In 1949, Kurt Gödel famously presented a solution of Einstein s generally relativistic field equations that permits the occurrence of closed timelike curves (CTCs). 1 According to Gödel himself, the possibility of CTCs confirms the idealist philosophy of time, namely what he takes to be the view that time is unreal, i.e., that the objective world is timeless: [I]t seems that one obtains an unequivocal proof for the view of those philosophers who, like Parmenides, Kant, and the modern idealists, deny the objectivity of change and consider change as an illusion or an appearance due to our special mode of perception. ([6], 202) Kriterion Journal of Philosophy, 2016, 30(2): c 2016 The author

94 92 KRITERION Journal of Philosophy, 2016, 30(2): Consequently, the inference drawn above as to the non-objectivity of change doubtless applies at least in these worlds [containing CTCs] [...] strengthening further the idealistic viewpoint. ([6], 205) [N]o reason can [hence] be given why an objective lapse of time should be assumed at all. ([6], 206) Nowadays, philosophers of physics disagree. They hold that even spacetimes containing CTCs have a temporal dimension (see, e.g., [4]; [5]; [9]). Thus, they are realists about time, at least as long as spacetime is time orientable. I agree that the occurrence of CTCs does not contradict the objectivity of time. It is unclear, however, in which sense time is objective or real, and, correspondingly, in which sense CTC-spacetimes have a temporal dimension. The analytic philosophy of time offers, roughly, two different views about what real time consists in: either it is B-time or A-time, i.e., either it is essentially the ordering of earlier-later or the directionality of a moving Now. I will argue that the possibility of CTCs is in conflict with B-time-order but requires A-time-direction. Then, the question arises of whether spacetime grounds A-time or rather the other way around: that presentness grounds spacetime, containing CTCs or not. I will suggest this latter option: universes containing CTCs motivate to develop a reasonable theory of presentism. The plan is as follows: In Section 2, I will briefly recap both the essentials of general relativity and of the analytic philosophy of time. Upon these physical and metaphysical basics, Section 3 provides the argument in favor of time directionality being more fundamental than ordering. Finally, Section 4 argues that presentness is more fundamental than spacetime. 2 Physical and Philosophical Basics The paper aims to demonstrate the relevance of the A- vs. B-time distinction for the ontology of relativistic spacetimes. This section presents the basic elements of general relativity and central themes from the current philosophy of time, as they are relevant for my purpose.

95 Cord Friebe: Presentist s View on Spacetime General Relativity To begin with, take a 4-dimensional (differentiable) manifold to represent spacetime. Every physically possible spacetime has a lightcone structure, i.e, with every spacetime point p is associated a lightcone such that the distinction between timelike, lightlike, and spacelike vectors is everywhere, at every p, available. In particular, a timelike vector points inside the lightcone and is conventionally called future-directed iff it points into the upper lobe (and past-directed otherwise, i.e., iff it points downwards). Then, spacetimes are time orientable iff a continuous designation of future-directed and past-directed for timelike vectors can be made over the entire manifold. 2 Figure 1: Time orientability: any continuous transport of a timelike vector must preserve its orientation. It should be emphasized that any simply connected spacetime is time orientable, a spacetime that is not time orientable is hence topologically strange. Consider, in particular, a timelike curve: a curve is called timelike iff its tangent vectors are always, at every point of the curve, timelike. Such a curve lies inside all of its lightcones. Given time orientability, one may say that such a curve is always future(or, past)- directed, and only given this, monotonically increasing parameters may consistently run along timelike curves the (even invariant) proper times along worldlines. Therefore, time orientability is generally taken to be a necessary condition for time to be real.

96 94 KRITERION Journal of Philosophy, 2016, 30(2): Figure 2: Proper time τ consistently parametrize every timelike curve ω. However, it is questionable whether time orientability is also sufficient for spacetime to have a temporal dimension. For it does not exclude the possibility that a timelike, even always future-directed, curve can be closed (or, almost closed). Intuitively, in such a case, the event located at a given starting point p precedes itself. Gödel s challenge precisely was that even Einstein s field equations allow for such a possibility so that it is not only mathematically compatible with time orientability but also physically possible. He concluded that the objective world is timeless. Still, it is undoubtedly not the case that the events on a CTC are simultaneous. Rather, the distinction between events being simultaneous and being non-simultaneous a distinction which seems to be crucially temporal is still available. Given this, one has good reason to sustain that universes containing CTCs are temporal. To sharpen the problem, it is instructive to confront an event/observer on a CTC with a freely falling body along a geodesic (see Figure 3): the hypothetical observer on the CTC is not simultaneous with any event on the CTC but, e.g., with the body/event located at p. However, (s)he is located at p more than once, namely modulo (periodic) τ ω. Does that mean and what exactly could that mean that the observer is again and again simultaneous with the body/event