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Causal Theories.

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Presentation on theme: "Causal Theories."— Presentation transcript:

1 Causal Theories

2 The absurdity of fit

3 The Absurdity of Fit In one sense, all the views we’ve considered in class so far are views on which meaning is a type of “fit.” On the idea theory, meanings (connotations) are ideas. Ideas have a certain pre-existing structure: just as in a painting the different parts are related to one another, and colored in various ways, and so forth.

4 Idea Theory and Fit In order to find out what an idea represents, we go out and find the things that best fit the idea, that most closely match its pre-existing structure, that best resemble it. Whatever best fits the pre-existing structure is what the idea represents.

5 Verificationism and Fit
While verificationism doesn’t have the same “little colored pictures” view of ideas or the resemblance theory of representation, it too involves a type of fit. In advance, words are associated with specific experiences that are stipulated to verify them. Why does a certain experience verify “That is red”? Because we said so, that’s why. We say in advance what experiences verify which sentences, then we go look and see what experiences we have.

6 Definitions and Fit Similarly, a definitions view is a type of fit as well. We say in advance what the definitions of words are. You don’t discover that bachelors are unmarried, you sit down and make it true by fiat.

7 The Absurdity of Fit But there’s something terribly wrong with the idea that meanings are specified in advance of our encounters with the world. That before any experience of the world, we sit down and draw up a structural description, or a set of experiences, or a verbal description and say “whatever I find that’s like this, I will call ‘a dog’!”

8 The Paradox of Inquiry The worry here is that on any of these models, you can’t be radically wrong. If ‘gold’ is true of what most closely resembles your idea of gold, then most of your beliefs about gold must be true. And the same goes for most of your beliefs about anything. If representation is what fits best with what you’ve drawn up in advance, in advance of inquiry, you can be pretty sure you already know what’s true and what isn’t.

9 The Paradox of Inquiry In fact, this problem is as old as Plato, and it’s called “the paradox of inquiry.” The paradox is: suppose you want to know, say, the nature of lightning. If you know what lightning is in advance, then you don’t need to investigate, because that’s what you wanted to know. But if you don’t know, how do you know when you discover it, that lightning is X? You find X, but you don’t know that it’s lightning, because you don’t know what lightning is!

10 Causal Theories Causal theories of meaning are radically different from the “fit” views we’ve been considering. They say (roughly) that a word or a concept represents what causes you to say it or think it. So even if all your beliefs about gold, and all your utterances concerning gold are completely false, those thoughts/ sentences still represent gold so long as gold is responsible for you believing/ saying them.

11 Causation in philosophy

12 A classic problem in philosophy since before Socrates is: “What is knowledge?” What’s the difference between believing something and knowing it?

13 A little reflection tells us that if you know something, then it has to be true. So maybe knowledge = true belief.

14 Socrates/ Plato vs. K = TB
Suppose there has been a murder, and no eye-witnesses Suppose the jury is superstitious, and I convince them that X is guilty, b/c I dreamed that he was.

15 Socrates/ Plato vs. K = TB
No one is inclined to say that the jury knows that X is the killer. But if I was accidentally right, they will have a true belief that X is the killer.

16 True Beliefs, Bad Reasons
Here the important point is that a belief that is true, but which you believe for bad reasons, is not really knowledge. If you believe something because you want to, or because your horoscope says it, or because a really unreliable person told it to you, then you don’t know it.

17 K = JTB This naturally suggests that for a belief to be knowledge, it not only has to be true, but has to be held for a good reason. This is the classic “JTB” account: knowledge = justified true belief.

18 Gettier Cases However, in the hyper-classic 1963 paper “Is Knowledge Justified True Belief?” Edmund Gettier provides reasons for thinking K ≠ JTB. Here’s an example of a “Gettier case.”

19 Russell’s Clock Everyday you (justifiedly) set your watch to the clock. Unbeknownst to you, last night the clock broke at exactly 8pm. You set your watch this morning to 8am, truly and justifiedly. It happens to be 8am.

20 The Causal Account of Knowledge
What’s going on here? Well, some philosophers (e.g. Dretske 1981) think that this shows knowledge isn’t justified true belief, it’s true belief that’s caused by the fact the belief is about.

21 Right Direction The causal account has its problems (can’t we know things about the future even though causation doesn’t go from future to past?), but to many it seemed like the right direction. To know something is to have your beliefs based on the facts, where “based on” is some sort of causal notion.

22 The Success of Causal Theories
Knowledge (Dretske): X knows proposition P = the information that P causes X to believe P. Action (Goldman): X performs action A = X’s beliefs and desires cause A. Perception (Grice): X perceives object O = O causes an experience in X. Representation?

23 Causation and representation

24 Motivations But why think that causation has anything to do with representation?

25 Motivations Why think causation has anything to do with mental representation?

26 The Mirror Universe

27 Secondary Qualities

28 Causation has the Right Structure?
Representation Resemblance Causation Non-reflexive Reflexive Irreflexive Asymmetric Symmetric Antisymmetric Intransitive Transitive

29 Structure Notice importantly that cases that show representation is non-reflexive rather than irreflexive, and asymmetric rather than antisymmetric include the semantic paradoxes: This sentence is false. Sentence #3 is false. Sentence #2 is true.

30 Possibility of Massive Error

31 Coordination across Theories
A related upshot is that two people with radically different theories can nevertheless be talking about the same thing, and hence be meaningfully disagreeing with one another.

32 The causal-historical account

33 Saul Kripke, 1940- Published first completeness proof for modal logic at 18. Highly influential in philosophy of language and mind. Developed the causal-historical theory of meaning

34 Saul Kripke, 1940- Kripke’s account is developed in his Naming and Necessity. The background is that he’s arguing against views on which the meanings of names are descriptions or definitions.

35 Against Descriptivism
Kripke argues that for any name N, there is no description D that we associate with N such that: If x satisfies the description, N = x. If N = x, then x must satisfy the description.

36 Ignorance & Error He argues against each claim as follows: Against #1: Arguments from ignorance. Sometimes lots of things satisfy the descriptions we associate with N, but only one is N. Against #2: Arguments from Error. Sometimes nothing satisfies the descriptions we associate with N (or some non-x does), but N still = x.

37 Ignorance: Feynman What people know: He’s a physicist He’s famous
He’s dead He worked on quantum mechanics

38 Ignorance: Feynman But Bohr: He’s a physicist He’s famous He’s dead
He worked on quantum mechanics

39 Ignorance: Feynman it’s not true that ‘Feynman’ means Bohr and it’s not true that it means nothing. How is that possible for the descriptivist?

40 Error: Einstein Who is Albert Einstein? What people believe:
Einstein is the inventor of the atomic bomb.

41 Error: Einstein But “the inventor of the nuclear bomb” can’t be the meaning of ‘Einstein’ because then ‘Einstein’ would refer to Leo Szilard (or whoever).

42 Kripke’s Picture “Someone, let’s say, a baby, is born; his parents call him by a certain name. They talk about him to their friends, other people meet him. Through various sorts of talk the name is spread from link to link as if by a chain…”

43 Kripke’s Picture “A speaker who is on the far end of this chain, who has heard about, say Richard Feynman, in the market place or elsewhere, may be referring to Richard Feynman even though he can’t remember from whom he first heard of Feynman or from whom he ever heard of Feynman.”

44 Kripke’s Picture “A rough statement of a theory might be the following: An initial ‘baptism’ takes place. Here the object may be named by ostension, or the reference of the name may be fixed by a description…”

45 Kripke’s Picture “When the name is ‘passed from link to link’, the receiver of the name must, I think, intend when he learns it to use it with the same reference as the man from whom he heard it.”

46 The Causal-Historical Theory
Let’s call that baby ‘Feynman’ Feynman Feynman Feynman Feynman

47 The Causal-Historical Theory
Let’s call that baby ‘Feynman’ Feynman Feynman Feynman Feynman Historical Chain of Transmission

48 The Causal-Historical Theory
Feynman Feynman Feynman Feynman Denotation

49 No Connotations The causal-historical theory, unlike the other theories we’ve considered so far, does not use a connotation (idea, experience, definition) to determine the denotation. Denotations are determined by non-mental facts.

50 Natural Kinds Kripke and another philosopher Hilary Putnam wanted to generalize what was true of names to “natural kind terms” (a phrase introduced by Quine).

51 Natural Kinds Kripke and another philosopher Hilary Putnam wanted to generalize what was true of names to “natural kind terms” (a phrase introduced by Quine).


53 The Causal-Historical Theory
Let’s call that thing a “tiger.” TIGER TIGER TIGER TIGER

54 Ignorance: Water In Hilary Putnam’s classic “The Meaning of ‘Meaning’” he argues that “meaning just ain’t in the head.” In particular, he presents his famous Twin Earth thought experiment, which is intended to show that what the word ‘water’ is true of is not determined by what we know or believe about water.

55 Twin Earth Twin Earth is a planet on the other side of the galaxy. In most ways, it is just like Earth, down to the smallest detail. You have a twin on Twin Earth who’s just like you, I have a twin who’s just like me, they’re sitting in a twin classroom, and my twin is giving a lecture just like this one to your twin. And so on and so forth.

56 Earth Twin Earth

57 Twin Earth There is however one difference between Earth and Twin Earth. On Earth, all the watery stuff is H2O. On Twin Earth, the watery stuff is composed of a complicated chemical compound we can abbreviate XYZ. H2O and XYZ look and behave exactly the same. They taste the same, they boil at the same temperatures at the same distance above sea level, their conductance is the same, etc.

58 Twin Earth Consider two twins, Arnold on Earth and Twin Arnold on Twin Earth. Neither knows any chemistry. What they know/ believe about the stuff they call ‘water’ is the same. Q: Would it be true for Arnold to call the stuff on Twin Earth ‘water’?

59 Twin Earth The intuition is supposed to be that, no, Arnold’s word ‘water’ is true of all an only H2O, whereas Twin Arnold’s word ‘water’ is true of all and only XYZ

60 The Moral The conclusion Kripke and Putnam draw from such cases is that we fix the referent of ‘water’ by a description like “the stuff around here in lakes and rivers and streams that falls from the sky and quenches thirst.” But this description only fixes the referent. If you replaced all the H2O on Earth with XYZ, there wouldn’t be any more water here.

61 Error: Gold Neither Kripke nor Putnam present any real cases where, through error, our beliefs about X are completely false of X, yet “X” still means X (like the Einstein case). (There’s probably lots of cases in contemporary physics.) But Kripke presents some imagined ones. Kant thought that the definition of gold was ‘yellow metal.’ Kripke then asks, “Could we discover that gold was not in fact yellow?” p. 118.

62 Imagine Gold’s Not Yellow
Kripke argues that we could. He asks us to suppose that something is weird about the air in places where gold is most prevalent. This strange air makes it appear that gold is yellow, but when we isolate gold in normal air, it’s obviously blue. Since this is clearly conceivable, it can’t be that gold means yellow metal, because if X means Y, then anything that is X is Y.

63 Error: Tigers Here’s a case from Paul Ziff in Semantic Analysis (referenced in Kripke p. 119 of 1980 edition). The Shorter OED has “the tiger is a large quadrupedal feline, tawny yellow in color, with blackish transverse stripes and a white belly.” Ziff argues that this can’t be what ‘tiger’ means, because if someone said “I just saw a three-legged tiger,” that wouldn’t be a contradiction.

64 Kripke goes on to argue that we could discover that something with none of the characteristics in the definition might still be a tiger. All previous zoologists who handled tigers were incompetent: they’re really lizards, they just look like felines. Their skin isn’t orange, because of optical illusions familiar from the gold case. Etc. The point is not that this is very likely. It’s that it’s conceivable, and it shouldn’t be (if definitions are meanings).

65 The Moral The moral of the story is that often our reference-fixing goes on in the absence of any true descriptions. Tigers are “those things over there, the dangerous ones that you don’t want to stand by.” We later discover that those things are felines, and have four legs, etc. But that’s not known in advance, as part of the meaning of ‘tiger.’ ‘Tiger’ applies to those things we initially baptized ‘tigers’ whatever they are.

66 The Epistemic Argument
Kripke had two other arguments against description theories (which he took to support his own account). First, suppose someone says “Aristotle means the last great philosopher of antiquity.” It is true that if x is named ‘Aristotle’ then x was the last great philosopher of antiquity and vice versa. So this is not a Feynman or an Einstein case.

67 The Epistemic Argument
However, it still seems as though you don’t have the same sort of epistemic access to this fact as to other clearer cases of definition like ‘bachelors are unmarried men.’ You don’t know for sure that Aristotle was the last great philosopher of antiquity. It could turn out false. It could turn out that Aristotle was just a medieval forgery. If it were a definition, you should know for sure. But you don’t.

68 The Modal Argument Finally, Kripke argues that the modal properties of names are different from those of definitions: FALSE: If things had gone differently, Aristotle might not have been Aristotle. TRUE: If things had gone differently, Aristotle might not have been the last great philosopher of antiquity.

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