Presentation on theme: "Theories of Mental Representation Part I. Vehicle vs. Content Small [horse picture][Small horse] picture."— Presentation transcript:
Theories of Mental Representation Part I
Vehicle vs. Content Small [horse picture][Small horse] picture
Vehicle vs. Content Representational vehicles are the things that represent (we can just call them representations: words, maps, photos, beliefs. The representational content of a representation is what it represents/ what it means.
Metasemantics Since most things dont have representational content, and only a few things do, its reasonable to ask: why do things like maps, sentences, and thoughts have content and rivers, lakes, and trees have no content?
Metasemantics Why is a map of Hong Kong a map of Hong Kong, rather than (say) a map of Kuala Lumpur? Why do representational things have the contents they do rather than some other content?
Metasemantics Metasemantics (metaphysical semantics, the metaphysics of meanings) is the part of philosophy of language that tries to answer the question: Why [in virtue of what] do representations have the contents they do, rather than some other content, or no content at all?
THE CONFORMAL THEORY
Aristotle Aristotle ( BCE) is in the running for greatest Western philosopher and hes usually in everyones top 5 at least. According to Aristotle, substances are composed of matter + form.
Aristotle on Hylomorphism Example: a house is a substance. The matter of the house is the bricks, cement, plaster, wood, and so forth. But the house is not just the bricks and cement, etc. It is those bricks, cement, plaster, etc. arranged in a certain way: with a certain form.
The Conformal Theory of Representation Aristotle held an obscure doctrine of the identity of the knower with the known. When I think of a house, for instance, my soul (i.e. my matter) takes on the form of a house. Thus, even though I (me, my soul, my matter) am distinct from a house (its matter), I represent the house because it and my soul have literally the same form (the form of a house).
Conformal Theory Represents
Aquinas and the Conformal Theory Aristotles greatest medieval follower, St. Thomas Aquinas ( CE), tried to deal with a problem in the conformal theory.
Problem for Conformal Theory Represents???
Intentional Presence The solution Aquinas proposed was that the house-form was not really present in me, it was only spiritually present. Spiritually present forms represent really present ones, but not vice versa. (Incidentally, this is also the explanation for why even though I have the form of a house, I dont look anything like a house.)
Conformal Theory Represents Real Form Spiritual Form
The Idea Theory The addition of spiritual forms to regular forms presaged what would become the dominant view of mental representations: the idea theory.
The Nature of Ideas According to Locke, ideas are the pictures drawn in our minds (Essay, II.x.5).
The Nature of Ideas An idea of a horse, then, is very much like a picture, image, or painting of a horse. Compare Hume: By ideas I mean the faint images of [perceptions] in thinking and reasoning (Treatise, I.i.1).
Idea Theory Mind Idea of a Dagger Dagger
Indirect Realism The idea theory is a variety of indirect realism. What you directly see are mental entities (for example, ideas). You only indirectly see the real things that the ideas represent.
Resemblance Theory According to the resemblance theory of representation, ideas represent things by resembling them– sort of like how painting works. The resemblance theory is thus a theory of what it is in virtue of which ideas have the contents they have: the ideas resemble the contents.
Idea Theory Mind Idea of a Dagger Dagger Resembles Sees
Corpuscularianism In the 17 th Century, corpuscularianim was the dominant scientific worldview. It held that all physical things are made of tiny little things called corpuscles. The theory was very similar to Greek atomism, with the exception that atoms couldnt be divided and corpuscles (in theory) could.
Corpuscularianism Part of the theory held that corpuscles only had shape, size, solidity, and motion. They did not have color, taste, texture, smell, or heat, though they could cause us to experience these things by exciting our sense organs.
Idea Theory Mind Idea of a Dog Dog Partly Resembles Sees
PROBLEMS FOR THE IDEA THEORY
4. PROBLEMS FOR THE RESEMBLANCE THEORY
Problems for Resemblance Theory 1.Cant distinguish concepts and propositions. 2.Resemblance is an equivalence relation, representation is not. 3.Resemblance is in some ways more and in some ways less determinate than representation. 4.Even photos and paintings dont represent what they resemble.
Concepts Concepts are representations of things or qualities: so I can have a concept of Obama, or a concept of red, or a concept of a horse, or a concept of a concept. Importantly, concepts are not truth-evaluable. My concept of red isnt true, and it isnt false either. It might be more or less accurate.
Propositions We can say that when I think of a thing, or think about a thing, then I am entertaining a concept. However, when I think that such-and-such, I am entertaining a proposition.
Propositions For example, I can think that Obama is the US president, or think that grass is red, or think that the concept of a horse is not a concept. Propositions are truth-evaluable: when I think that grass is red, my thought is false. (Not so when I just think of red.)
The idea theory seems to have trouble distinguishing concepts and propositions. According to the idea theory, thought is having ideas, and ideas are like mental pictures. Are mental pictures truth-evaluable? If they are, then concepts arent ideas. If they arent, then propositions arent ideas.
Resemblance as an Equivalence Relation Resemblance, like identity, is an equivalence relation, meaning its reflexive, symmetric, and transitive: Reflexive: for all X, X resembles X. (Everything resembles itself.) Symmetric: for all X and Y, if X resembles Y, then Y resembles X. Transitive: for all X, Y, and Z, if X resembles Y and Y resembles Z, then X resembles Z.
Problem for the idea theory: resemblance is an equivalence relation, but representation is not. Therefore representation resemblance.
1. Representation is Not Reflexive You can have a representation that represents itself (for example, a map of Hong Kong that includes the maps location), but most representations dont represent themselves. You can have a painting of a horse, that is not a painting of a painting of a horse (not a painting of itself).
2. Representation is Not Symmetric Most of what gets represented is not representational. My thoughts represent lakes and rivers and trees, but lakes and rivers and trees dont represent my thoughts. And even when I do represent representations (when I think about a painting, say), usually they dont represent me or my thoughts.
3. Representation is not Transitive The directory at the museum might represent the location of a certain Picasso painting. That painting could represent a horse. But the directory doesnt represent any horses, it only represents paintings.
Indeterminacy and Error Another class of problems for resemblance theories of representation involve indeterminacy and error.
Wittgensteins Man on the Hill A picture which corresponds to a man walking up a hill forward corresponds equally, and in the same way, to a man sliding down the hill backward. -- Philosophical Investigations
Wittgensteins Man on the Hill Perhaps a Martian would describe the picture [as the man sliding down]. I do not need to explain why we do not describe it so. Representation can be more determinate than resemblance.
Twins Suppose you met a woman last night and I met her twin. You and I both have memories (mental representations) of the women we met, and lets suppose those mental images are identical in every respect.
Twins Here, even though the representational vehicles are the same, and thus resemble the exact same things, the representational contents are different.
Error Consider a revised version of the twins case: you and I separately meet each of two twins. They are exactly alike except that the twin you meet has a scar on her left cheek and mine has no scar.
Error However, the next day I falsely remember my twin as having a scar on her left cheek. Then the resemblance theory says my memory is about the twin you met. Someone Ive never met in my entire life!
Massive Error Imagine that I have a pen pal whom Ive never met, or seen a picture of. Over the course of our correspondence, I develop an elaborate mental image of her: what color her hair is, how big her nose is, etc. Suppose that my mental image is completely wrong and doesnt resemble my pen pal at all.
Massive Error On the resemblance view, it would seem that I was incapable of thinking about her, for example, I couldnt think: Oh, heres another letter from my pen pal!
Conceptual Competence One direction for a solution to the problem of error is to say that my idea of my twin or my pen pal is only a partial idea or is an incompletely grasped idea or something like that.
Conceptual Competence That may be true, but this doesnt really resolve the problem. Why is the idea– partial or incomplete as it is– an idea of my pen pal, rather than of someone else whom it more closely resembles, or of a mere fiction?
Fodor vs. the Image Theory Fodor holds that thought happens in a language (the language of thought) rather than in images– the ideas of the idea theorist. One argument goes like this: you can see a Necker cube in two different ways. Theres one picture that corresponds to two ideas. But if ideas are just mental pictures, what two different mental pictures correspond to the two different ways you can see the one physical picture?
Seeing vs. Seeing-as What the Necker cube example suggests is a more general problem. You can look at the Fischer cow and not see that it is a cow. When you see the picture as a cow, your perception changes. But if your idea of the picture is just a copy of that picture in your head, what about it changes such that once it was just squiggles and then its a cow?
Fodor vs. the Image Theory Another argument is that the idea theorist doesnt have a good story about my thought that I am NOT wearing a red shirt. Is it a picture of me wearing a blue shirt? Or a green one? What if Im just thinking that Im NOT wearing a red one, but not thinking of what color shirt I am wearing? Notice how No smoking signs have to resort to non-pictorial symbols. You cant just have a sign where someone isnt smoking.
Perhaps the biggest problem for the idea theory is that in most cases where x resembles y, x does not represent y. Two cows for instance might resemble each other much more than our ideas, paintings, or photographs resemble them. Yet we have no inclination to say that the cows represent each other.
Hilary Putnam points out an interesting case. Imagine two lines in the sand. One has been drawn by a human with the intention of tracing the figure of Winston Churchill, and it resembles him (or his figure) a lot. The other has been traced by an ant just wandering aimlessly in the sand. But imagine that the ants line is identical to the humans. We think the human-drawing represents Churchill, but the ant-line doesnt.
This suggests that drawings, paintings, and so forth dont represent things by resembling them. They represent things on the basis of our intentions. But the entire motivation of the idea theory was to model ideas on drawings and paintings. Those things represent by resembling, and thats how ideas were supposed to work as well.