Relative Thoughts. Dr. Sanna Hirvonen Junior visiting fellow, Universita Degli Studi di Milano

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1 Relative Thoughts Dr. Sanna Hirvonen Junior visiting fellow, Universita Degli Studi di Milano 1

2 Course schedule Lecture 1, Mon 16 th Oct, 10-12am: Propositions as contents of thought and language Lecture 2, Tue 17 th Oct, 2-4pm: Relativising propositions Lecture 3, Wed 18 th Oct, 2-4pm: Relative propositions in thought and communication I Lecture 4, Thu 19 th Oct, 2-4pm: Relative propositions in thought and communication II Lecture 5 (talk), Fri 20 th Oct, 4-6pm: The Time-Lag Argument, Direct Realism about Seeing, and the Extended Now Readings: Lecture 1: Gottlob Frege Thoughts (1918) Lecture 3: Max Kölbel Faultless Disagreement (2003) 2

3 The aims of the course I To introduce some core ideas in philosophy of language: How to understand contents of thought & language: propositions The role of truth in an account of meanings of sentences: truthconditional semantics The context-sensitivity of language Extensional vs. intensional semantics (possible worlds semantics) 3

4 The aims of the course II To introduce a recent debate in philosophy of language: Absolute truth vs. relative truth: does relative truth make sense? Are there propositions that are only relatively true? If so, in which field is relativism true? Aesthetics, taste, morality? If relativism is true, what follows? 4

5 Lecture 1: Propositions as contents of thought and language The aims for today: To understand the classic view of propositions as contents of thought and language, and as the bearers of truth-values. Reading: Gottlob Frege Thoughts (aka The Thought ) (1918) Formulates what became the standard view of propositions, and states a variety of problems that have since occupied philosophers of language. 5

6 Some basic questions about language The sentences (a)-(c) all mean the same thing. (a) La neve è bianca (b) The snow is white (c) Lumi on valkoista How do we know that? 6

7 Truth-conditions Declarative sentences like (a)-(c) are used to express how things are, i.e. what is true of the world. We know that (a)-(c) mean the same because they are true under the same conditions: they are true if and only if snow is white. Generally: for any two sentences, they mean the same if and only if they are true under the same conditions. 7

8 Truth-conditional semantics Semantics: theory of meanings Truth-conditional semantics: We give the meanings of sentences by giving their truth-conditions. Simplified version: Snow is white iff snow is white. Use vs. mention: --- on the left side of the bi-conditional mentions a sentence, the right side uses the sentence. 8

9 Some more basic questions How can (a)-(c) mean the same (= have the same truth-conditions)? Don t different languages cause people to think different thoughts? 9

10 Reference & compositionality snow, neve, lumi all refer to snow bianca, white, valkoinen all refer to the property of whiteness. Reference to objects / properties in the world (partially) determines word meanings. The mode of composition of words together with word meanings determines the meanings of sentences. E.g. The snow is white and The white is snow don t mean the same (=not true under the same conditions). 10

11 Reference That words get their meanings partly via reference to objects and properties is crucial for shared meanings. We all perceive the same world and interact with it: language enables us to communicate about it. Truth is an essential notion because it allows us to show by reference to the world what sentences mean. 11

12 Back to truth-conditions Some expressions mean different things in different contents: e.g. I, here, now. Thus, a sentence like I am here now cannot be given truthconditions. Instead, truth-conditions are given to uses of sentences in contexts = utterance contents. I am here now as uttered by a speaker S, in context C is true iff the speaker of the context is at the location of the context at the time of the utterance. 12

13 Utterances Uses of declarative sentences: they state something about the world. They are either true or false. Utterances express beliefs. A speaker expresses a belief by an utterance; a hearer (if they believe what the speaker says), comes to believe the content of that utterance. What is the content that is thus shared? 13

14 Propositions We say that the content of an utterance is a proposition (= propositional content = Frege s thoughts) Utterances express propositions. Beliefs have propositions as contents. In successful communication, the speaker expresses a proposition, and the hearer grasps the same proposition. As a consequence, both believe the same proposition. 14

15 Propositional attitudes I Mental states whose object is a proposition. Typically recognizable by that-clauses: Laura believes that <her boyfriend is cheating on her> Alex hopes that <he won the lottery> Peter knows that <2 + 2 = 4> Other attitudes: desiring, wishing, imagining, doubting, regretting Some attitudes can have propositions or objects as attitudes: seeing, hearing, fearing, loving, dreaming etc. 15

16 Propositional attitudes II Core case: belief. An utterance expresses a belief by default, whereas with other propositional attitudes they must be stated. Beliefs are true or false. Related states: Agreement: two people agree over a proposition p when they both believe p. Disagreement: two people disagree over a proposition p when one believes that p and the other believes that not p. 16

17 Propositional attitudes III Makes sense of knowledge: Knowledge requires something objective as its content. True propositions (= facts) provide the suitable object. Propositions allow us to explain how we can have different attitudes towards the same content: I fear that p, you believe that p, Sue regrets that p etc. The shared content between different attitudes can explain the relations between those states: e.g. knowing that p requires believing that p; suspecting that p requires not knowing that p etc. 17

18 What are propositions? Objective: they can be identified by reference to the world. E.g. Socrates was a bouncer in a night club expresses a false proposition. We can understand it, even if it describes a state that never existed, i.e. it is not concrete. Nor is it merely an idea of mine, since you can all equally grasp the proposition. 18

19 The nature of propositions For simplicity, best to think of them as abstract. Abstract objects are needed anyway: objects of mathematics, sets, classes, the alphabet, works of literature etc. Many attempts at naturalizing propositions; let us set aside the issue of their nature for now. 19

20 Example Axolotls are extinct reads Anna in Facebook today. She thus comes to believe the proposition <Axolots are extinct in October 2017> Later that day she meets Boris, and tells him Axolotls are extinct, thus expressing the proposition she earlier came to believe. 20

21 Example By understanding what she said Boris grasps the proposition she expressed. But he doesn t trust Anna, and instead disbelieves the proposition <Axolotls are extinct in October 2017>. Anna and Boris disagree, since Anna believes the world to be without axolotls, and Boris believes the world still has axolotls. (Luckily, Boris is right!) 21

22 Summary so far Propositions allow for a unified explanation of contents of a variety of mental states. By taking propositions also as contents of utterances, we can explain communication: how those same mental states are expressed by the use of language. Given that propositions are the bearers of truth-values, they explain how we can know things: we are knowledgeable when we believe true propositions, i.e. facts. 22

23 Problem I: cognitive value Propositions are supposed to be the objects of attitudes. Co-referring terms can be substituted in truth-conditions: E.g. Hesperus shines is true iff Phosphorus shines, as Hesperus = Phosphorus. Suppose Socrates does not know that Hesperus = Phosphorus. He is looking at the sky in the evening, and states <Hesperus shines>. But he would explicitly deny the truth of <Phophorus shines>. But they are the same proposition! 23

24 Problem I: cognitive value The same problem plagues all propositional attitude ascriptions. Frege s solution: expressions have both a reference and a sense. The sense is the mode of presentation of the reference. E.g. Hesperus and Phosphorus both refer to Venus, but they have different senses. Frege: thoughts are senses of sentences. But now, what are senses? 24

25 Senses Modes of presentation of reference. E.g. The sense of Hesperus =/= the sense of Phosphorus There are thus more senses than there are referents. Frege: thoughts are senses of sentences. E.g. names, the indexical I : The referent can be thought of differently by different speakers. 25

26 Senses Frege: in propositional attitude reports, names refer to their sense, not their ordinary reference. Consequence: communication breakdown! (Dr. Laubens case) Propositions lose their objectivity. E.g. Dr. Laubens was wounded, uttered by me now. Sanna believes that <Dr. Laubens was wounded>. Not the same proposition! But an utterance is an expression of belief! 26

27 The problem of senses For any object, there are innumerable modes to represent it. E.g. Aristotle: One of Plato s students, my neighbour, the polite man with a beard, the most important philosopher Not objective: for senses to do their work, inaccurate modes of representations must be allowed too. The core issue: The relation between words and propositions becomes unclear. Propositions do not compositionally reflect their parts anymore. 27

28 Problem II: indeterminacy Most sentences we use do not state their full truth-conditions: E.g. I ve had breakfast is true when? When I ve had breakfast at least once in my life? When I ve had breakfast today? Why today? We communicate with such statements. But, to express propositions they must be truth-evaluable. The missing elements, e.g. time, must be added. But how? Where does it come from? 28

29 Problem II: indeterminacy Context-sensitive expressions: Jane is tall ; Milano is a big city ; I ll be there soon What determines the propositions expressed by these? The context cannot operate independently of speakers. Problem similar to the senses: how can we communicate? 29

30 Problem III: non-truth-conditional contents Lucy is rich and lovely vs. Lucy is rich but lovely I sold my horse vs. I sold my nag Alfred is still not here vs. Alfred is not here These expressions add nothing to the truth-conditions, or even to the senses according to Frege. But they communicate different contents! Is there content beyond propositions? What is it? 30