PHIL 5983: Naturalness and Fundamentality Seminar Prof. Funkhouser Spring 2017 Week 8: Chalmers, Constructing the World Notes (Introduction, Chapters 1-2) Introduction * We are introduced to the ideas of a Laplacean demon, Laplacean truths, and a Laplacean intellect. The Laplacean demon would, supposedly, be able to calculate every (physical) truth about the world. This is an example of what Chalmers calls a scrutability thesis. It says that the world is in a certain sense comprehensible, at least given a certain class of basic truths about the world. In particular, it says that all truths about the world are scrutable from some basic truths. (xiii) Chalmers goes on to distinguish four different scrutability theses: Laplacean, Inferential, Conditional, and A Priori. The original Laplacean thesis concerned only physical basic truths. But one might have worries due to indeterminacy, consciousness, morality, etc. that this basis is insufficient to cover all truths. So, more could be added. However, we still want the base to be compact (say, in the spirit of Lewis s natural properties). The scrutability thesis he ends with states that all true propositions about the world could be known a priori by a Laplacean intellect. The book is devoted to making the scrutability thesis precise, articulating the basic truths, and showing what can be derived from them. It has wide application to various core areas of philosophy. He uses it defend the analytic/synthetic distinction, Fregean senses, and internalism about mental content. * The book s project is supposed to be similar to that adopted by Rudolf Carnap, especially his Aufbau (1928). (This is reflected in Chalmers s choice for a title.) the aim is to specify the structure of the world in the form of certain basic truths from which all truths can be derived. (xviii) Though, Chalmers is not a logical empiricist! (Chalmers is actually more of a rationalist.) No verificationism, no phenomenalism. * He claims that it is a work of metaphysical epistemology: epistemology in service of a global picture of the world and of our conception thereof. (xx) This culminates (for us, at least) in the sixteenth excursus, where scrutability is applied to supervenience and grounding. (He projects three books covering the golden triangle : reason, meaning, and modality.) Chapter 1 1.1 1
* Thoughts seem to be composed of simple concepts think of Locke s simple ideas. Various philosophers (Locke, Russell, Carnap) and scientists (e.g., linguists) have sought to provide their own inventory of these primitive concepts. Carnap went to the extreme, arguing for a single primitive concept (plus logical concepts)! This concept was phenomenal similarity among experiences had by a subject at different times. For example, concepts of specific sensory qualities, such as that of a certain shade of red, are defined in terms of chains or circles of similarity between experiences. (3) All higher-level phenomena are built up from simple sensory concepts in a progression: spatiotemporal, bodily, behavioral, psychological, cultural. All the above projects share a commitment to Definability: Definability: There is a compact class of primitive expressions such that all expressions are definable in terms of that class. (3) There will be different forms of definitional statements for the different grammatical categories to be defined. Adequate definitions must be both extensionally and intensionally (analytic, a priori, or necessary) adequate. Carnap only required extensional adequacy, but that will not get us the right connections to meaning, knowledge, and modality. There may be other definitional criteria as well: psychological, formal, conceptual, etc. From Definability, we are led to Definitional Scrutability: Definitional Scrutability: There is a compact class of truths from which all truths are definitionally scrutable. (5) Definitional statements serve as bridges between higher-level truths and the base. For Carnap, phenomenal truths make up this compact class of base truths. If definitions must be known a priori, then we are led to A Priori Scrutability: A Priori Scrutability: There is a compact class of truths from which all truths are a priori scrutable. (6) This obviously makes the project epistemological. 1.2 * It is clear that Carnap s Aufbau project was a failure. Chalmers provides four prominent objections to Carnap s attempt to reduce everything to phenomenal experience plus logic (which lead to his phenomenalism and verificationism). But Chalmers claims that this is merely due to Carnap s poor choice in primitive concepts. (Carnap himself soon abandoned phenomenalism for a physicalist approach.) We should expand it so as to include concepts for physical properties, causation, etc. 2
Others have expressed skepticism about definitional statements. Such definitions might be impossible given the open texture or family resemblances to which the expressions give rise. And Quine and Kripke, in their distinctive ways, denied that definitions align with having the attributes of analyticity, a priori, and necessity. Most of these problems show that definitions almost invariably succumb to counter-examples. 1.3 * Even if we cannot define some term E, we often can answer E-questions that are couched completely in some other vocabulary, D. Something like this happens throughout philosophy, psychology, and other areas. We are given a description D of a scenario without using a key term E, and we are asked to determine whether and how the expression E applies to it Often we have no trouble doing so. (13) This is a kind of a priori scrutability that does not require definability. Even if there is a definition to be had connecting E to D-terms, we do not need to know it to make our judgment. 1.4 * Carnap later moved to intensions to capture how an expression applies to a range of possible cases. The intension of a sentence is a function from scenarios to truth values. Intensions for smaller expressions will be functions from scenarios to extensions of different sorts. Chalmers claims that we can grasp intensions without grasping definitions. Counter-examples can refute definitions, but they actually rely on intensions. Think of Gettier cases and Kripke s Aristotle example. The modal profile of know can be represented as an intension that classifies Gettier cases as cases in which knowledge is absent. Likewise, the modal profile of Aristotle can be represented as an intension that picks out Aristotle in the situation in which he never went into pedagogy, rather than picking out Alexander s teacher. (18) Definitions are not identical to either the modal or epistemic profiles of expressions. Chalmers will eventually defend a Fregean account of meaning from Kripke s arguments. 1.5 * What goes into the scrutability base? Candidates have included logical, phenomenal, and microphysical expressions. Chalmers wants a compact class of expressions -- compact in the sense of coming from few families (e.g., conceptual schemes) of expressions. We should not expect many natural language categories (e.g., natural kind terms, names, etc.) to appear in this class. Instead, such expressions will likely be derivative from more primitive expressions. Plus, no trivializing mechanisms. 3
Chalmers favors a minimal scrutability base that includes: physics, qualia, that s all, and indexicals (PQTI). Alternatives have included: Structural Scrutability, Fundamental Scrutability, and Acquaintance Scrutability. More expansive scrutability bases might allow normative (e.g., ought ) or intentional (e.g., believes ) expressions. One could even be a pluralist about minimal scrutability bases. 1.6 * A Priori Scrutability can revive the Aufbau program, but without committing to such a sparse base or the definitional requirement. Quine s challenge to the a priori/a posteriori distinction still looms, though. A Priori Scrutability has applications to: Skepticism, Modality, Meaning, Mental Content, Metaphysics, Scientific Analysis, and Metaphilosophy. Chapter 2 2.1 * There are both restricted (e.g., all mental truths from physical truths) and unrestricted scrutability claims. Chalmers is mainly focused on unrestricted theses. These have three elements: truths, scrutable from, and base. Each element has variations, with Chalmers s default being: sentential, a priori, and compact. Note the role of idealization in the scrutability relations. And all these scrutability theses also admit of a formulation in terms of something stronger than mere knowledge knowledge with certainty (conclusive). 2.2 * What kinds of things are the truths in scrutability theses? Propositions, sentences, utterances, beliefs? Chalmers reminds us of the different positions people take on propositions: possibleworlds views, Russellian, Fregean, and eliminativist. Different answers here lead to different conclusions concerning what is a priori scrutable. Chalmers wishes, then, to remain neutral on propositions for now. This is also because he eventually wants to argue for the Fregean view, so he should not just assume it at the outset. So instead of focusing on proposition formulations of scrutability, Chalmers primarily will consider sentential (linguistic) formulations. The key idea there is to analyze the epistemic status of a sentence S in terms of epistemic properties of mental states that S expresses or is apt to express. For example, one knows S when one has knowledge that is apt to be expressed by S. Likewise, one knows S a priori when one has a priori knowledge that is apt to be expressed by S, and one believes S when one has a belief that is apt to be expressed by S. (46) 2.3 * Inferential scrutability consists in being in a position to know certain sentences from base sentences, typically (though not necessarily) by inference. 4
A subject s at time t is in a position to know S when it is possible that s comes to know S at some later time t, starting from s s position at t and without acquiring any further empirical information. (49) For now I will ignore the complications related to Fitch s paradox of knowability. 2.4 * Conditional scrutability obviously is conditional. It consists in being in a position to know that if certain sentences are true then so are certain others. We can think of conditional belief in terms of Ramsey s conditional credences. Conditional knowledge adds new complications. Chalmers assumes that some credences are rational for a subject. We can then say that p is conditionally scrutable from a class of propositions c, for a subject, when the subject s rational conditional credence cr (p c) is high, where cr (p c) is stipulated to be cr (p cc), where cc is a conjunction of all the propositions in c. (56) We can then make recourse to the connections between beliefs and sentences from before to get conditional credences for sentences. 2.5 * Sentences can be a priori scrutable relative some classes of sentences (but not others), as well as for some subjects (but not others). 2.6 * We can also consider Generalized Scrutability, which claims a base from which all truths (no matter what the world is) are scrutable. Such a base would have to include alien properties. 2.7 * Scrutability is an idealization that goes beyond our actual cognitive abilities. The idealizations cover our capacities for thought (concepts, complexity) and reasoning (calculation, etc.). 2.8 * Chalmers consider four objections to idealization: 1. Coherence: This objection holds that idealization is not well-defined. Chalmers simply denies this skepticism about better and worse ways of reasoning. 2. Knowledge: How could we ever know the idealization facts? Chalmers says that we do not need to know these. 3. Triviality: Isn t it trivial that an ideal reasoner would know these truths? No, it is not trivial that an ideal reasoner would know, say, that there is a table in this room. This could not be known a priori. Ideal reasoners still reason they do not know by magic. 4. Applicability: But what do the powers of ideal reasoners have to do with the situation of actual, non-ideal reasoners? It can point out where our ignorance lies, even if it does not give us optimism about actually acquiring such knowledge. Scrutability with idealization can also be used to define intensions, which has many applications. 5