1. Folk Psychology Eliminativist Materialism & Instrumentalism

2. Follow-up to question last week: “how can anyone still take the massively modular theory of mind seriously, given all the counter-evidence?”

3. Folk Psychology Folk psychology (FP): Folk: ordinary people, non-professionals Psychology: The theory and practice of explaining, predicting and manipulating other people’s thinking and behavior Folk psychology: the common sense understanding of the mind

4. Examples of folk psychology in action A: Why is John studying hard? B: He wants to pass the test, and he thinks that if he studies hard he will pass. A: Why did you tell Paul that I was sick? B: Because I wanted him to think that you wouldn’t be here, so he wouldn’t come over to see you. Folk psychology uses beliefs and desires to explain behavior.

5. Beliefs and desires are propositional attitudes. Propositional attitude: a mental state relating a person to a proposition i.e. intentional mental states expressible with a “that” clause examples: beliefs, desires, hopes, fears “I believe that it is raining”, “I hope that it will stop”, “I fear that it will not” FP relies on propositional attitudes. If George desires A, believes that B will cause A, then George desires B (other things being equal.) Folk psychology = belief-desire psychology = propositional attitude psychology

6. LOTH and Folk Psychology The main motivation for the language of thought hypothesis, and its biggest strength is that it coheres with folk psychology. LOTH naturalizes folk psychology That is, it provides a naturalistic explanation of how beliefs and desires can exist in the brain, how they can interact, and how they can lead to action Naturalistic: materialistic, not supernatural

7. Through LOT, beliefs and desires are reduced to symbols, symbols can be manipulated according to logical laws (e.g. if “P” and “if P then Q”, then “Q”). Example: If John believes X, and X entails Y, John believes Y. Example: If John fears X, John desires that not X. Conclusions can be implemented directly as actions: I want milk & I believe that I can get milk at the store  I should go to the store  I go to the store Reason can be mechanized. LOTH is a realist theory of propositional attitudes. i.e. in LOTH, propositional attitudes are said to be literally instantiated in the brain as symbolic sentences. Beliefs and desires are literally sentences written in the brain in encoded mentalese (or natural language).

8. Eliminativism towards Folk Psychology Paul Churchland’s stance: 1) Folk psychology is a theory 2) The theory is wrong 3) Folk psychology should be eliminated.

9. Churchland’s stance (cont.) The “theory theory” of folk psychology: Folk Psychology is a theory FP posits the existence of entities: beliefs, desires, etc. as literally instantiated in the brain. FP posits laws governing the interaction of these entities, and the relation between these entities and action. FP makes predictions based on these hypotheses.

10. Churchland’s stance (cont.) Folk psychology is a bad theory 1) Explanatory failures 2) Stagnant and unproductive 3) Not coherent with other scientific knowledge

11. 1) Explanatory failures FP fails to provide any explanation for many processes of the mind e.g. mental illness, creative imagination, intelligence differences between individuals, sleep, ability to perform physical actions such as catching a ball, memory, and especially learning, e.g. learning concepts Note: Churchland admits that these failures do not show FP is wrong, but they do show FP is limited. A supporter of FP can argue, that FP does not attempt to answer most of these concerns. It is primarily a theory concerning conscious thought, decision-making and action, and is not concerned with physical actions, sleep, mechanics of memory, etc.

12. 2) Stagnant and Unproductive. Churchland calls FP a theory of “retreat, infertility and decadence”. i) Retreat: domain of FP used to extend to wide range of natural phenomena such as angry sea, jealous moon, angry volcano, etc. ii) Infertility and decadence: No progress made in FP since ancient Greek times. Still use same concepts to explain people’s actions, with about same degree of success at predicting and manipulating people’s behavior.

13. 3) Not coherent with other scientific knowledge in other fields e.g. evolutionary theory, biology and neuroscience. Other disciplines support each other, FP is isolated. Churchland claims that science can explain human being’s constitution, development and behavioral capacities through physics, chemistry, evolutionary theory, biology, physiology and neuroscience and that using these explanations, science can outperform FP even in its own field.

14. Folk psychology should be eliminated. FP should be replaced by a neuroscientific understanding of the brain that does not posit such entities as beliefs, desires, etc.

15. Churchland’s alternatives to FP Churchland provides two highly-speculative, science fictiony ideas of what could someday replace folk psychology: A) New language. With new understanding of the structure of the brain, we may develop a new, more powerful language for deeper communication. This new language could completely replace all natural languages. New language would not use concepts of belief, desire, etc., so FP would be eliminated.

16. B) Communication by physically connecting brains together. The corpus collosum is a cable of neurons connecting the two hemispheres of our brains. Split-brain patients have had the corpus collosum cut, and the result is that the two halves of their brain do not communicate well. So, the corpus collosum provides communication between the two halves of our brains. Churchland’s idea: someday people may be able to connect brains (i.e. the brains of two different people) with an artificial corpus collosum. Two people could understand each other like two halves of one brain understand each other. Again, communication by natural language, and hence FP, would be obsolete.

17. Responses to Eliminativism Response to “FP is stagnant”. One response is to deny that FP in itself is stagnant. FP has incorporated many modern ideas from psychology, such as unconscious or repressed desires, phobias, personality types, such as neurotic, anal recessive, etc. “Folks” (non-professionals) do now use these concepts, even when not in proper psychological way. So-called “psycho-babble”. So FP is adaptive, flexible, and able to incorporate ideas without collapsing.

18. Responses to FP is stagnant (cont.) Sterelny’s response: FP is an important component of cognitive psychology (e.g. representative theory of the mind). Cognitive psychology is progressive and undertakes research programs to understand learning, memory, etc. Therefore, FP is not stagnant.

19. FP is an important component of cognitive psychology also answers Churchland’s other points of FP’s explanatory failures and FP’s not cohering with science. If FP is an important part of cognitive psychology, and cognitive psychology attempts to answer the failures Churchland mentions, and coheres with other scientific disciplines, then FP is indirectly engaged in answering explanatory failures and cohering with modern scientific advances. Folk Psychology  Cognitive Psychology  progressive, scientific, investigating sleep, learning, etc.

20. Possible rejoinders by eliminativists i) Deny that folk psychology is an important component of cognitive psychology. Fodor’s theories obviously rely on the concepts of FP, but others, like Steven Stich, think that cognitive psychology should be free from FP concepts. ii) Deny that cognitive psychology is progressive and coherent with modern science. Churchland thinks Cognitive Psychology is wrongheaded precisely because of its reliance on FP concepts.

21. Churchland’s Attack on a Functionalist Characterization of FP The target: A functionalist definition of propositional attitudes (as posited by FP): Beliefs, desires, etc. may not correspond to any particular physical objects in the brain, but are defined as functional states. Churchland’s response: Compares functional definition of FP entities to (fictional) functional definition of the entities and principles of alchemy

22. Alchemy A medieval science engaged in: combining and mixing elements, concocting medicine attempting to transform base metals (iron, lead, etc.) into gold Alchemy had an elaborate theory, including the idea that all elements were made up (or “ensouled by”) four fundamental spirits: Mercury, Sulpher, Yellow Arsenic and Sal Ammoniac. Alchemy was replaced by the rise of modern chemistry.

23. The Alchemy-FP comparison Churchland imagines alchemists trying to save alchemy by creating a functional definition of alchemy terms e.g. “ensouled by mercury” means “having certain properties such as being shiny, liquifying under heat, etc.” Alchemists could continue using alchemy concepts, while admitting that all elements are not literally, physically made of up Mercury, Sulpher, Yellow Arsenic and Sal Ammoniac. Churchland’s argument: It would be pointless for alchemists to try to save alchemy this way. Better to admit that alchemy is a bad theory and eliminate it. Likewise, people should not try to save Folk Psychology in this empty way (redefining terms as functionalist concepts). Better to admit FP is a bad theory and eliminate it.

24. Sterleney’s response to Alchemy comparison: Churchland makes a good point, but says that he only proves that functionalist terms may be empty, but not that they always are. Many terms used in science are functionalist, such as definition of heart, eye and gene. So functionalist terms can be useful. Cognitive psychology functionalist terms are useful.

25. Instrumentalism and the Intentional Stance Daniel Dennett’s response to eliminativism. Explained in “Two Contrasts: Folk Craft vs. Folk Science, and Belief vs. Opinion” Dennett’s position: 1)FP is essentially a craft, not a theory 2)Even if FP has a theory, the theory could be wrong, but the practice still good. 3)FP is a type of intentional stance. The intentional stance is useful.

26. 1) FP is essentially a craft, not a theory. Dennett calls it “Folk Craft” FP is fast, efficient, sometimes wrong. Compare folk physics Folk physics is fast: people respond quickly to the situation of water running off table (by jumping away to avoid getting wet) and yet respond differently and equally quickly when the table has lip to catch the water (no need to jump back). But folk physics is sometimes wrong, e.g. siphon. Likewise, folk psychology is fast and efficient, but sometimes wrong, and can be improved on by science.

27. 2) Even if FP has a theory, the theory could be wrong, but the practice still good. Dennett’s example: airplane pilot. A pilot may have the wrong theory of flying and yet be a good pilot. My example: Traditional Chinese Medicine (TCM) Theory: yin and yang, 5 elements: fire, wood, earth, metal, water, meridians Theory appears to be wrong. Nothing in the body corresponds to yin and yang, meridians, etc. However, practice still has value. If TCM is sometimes more effective than western medicine, TCM may be worth saving in spite of wrong theory. Don’t throw away the baby with the bathwater.

28. 3) FP is a type of “Intentional Stance”. Three stances: Intentional Stance Design Stance Physical Stance (Similar to 3 levels of description: environmental level, computational level and physical level) Intentional stance: Attributing beliefs and desires to people (animals, computers, etc.) to predict and manipulate behavior.

29. Intentional stance -- natural human way to explain animal behavior, behavior of computers, etc. e.g. the mosquito flies erratically because it doesn’t want to get caught e.g. the chess-playing computer thinks it should get its queen out early Computers (and mosquitos) are too complicated to explain via the physical stance, or even the design stance. So the intentional stance is necessary and unavoidable. Taking the intentional stance is automatic for humans, see: http://www.pnas.org/cgi/content/full/0308220101/DC1#F1

30. The intentional stance is fast and effective. Is it an accurate description of what goes on in the brain? That concerns the design stance, and the physical stance. Dennett: the details of the design and physical make-up don’t matter to intentional stance. Example: raccoon trap. To catch a raccoon, suppose the raccoon is rational. Then you can outwit him. What goes on in the raccoon’s brain? Who knows? Intentional stance is necessary for understanding other people. Evolutionary psychology not detailed enough for specific use. Physics, biology, neuroscience, etc. too detailed to be practical. Nothing approaches FP in usefulness, and likely never will

31. Dennett’s Intentional Stance vs. Fodor’s Language of Thought Hypothesis Dennett: FP is a useful fiction, an abstraction (like a center of gravity) Beliefs and desires are not literally encoded in the head No literal language of thought Fodor’s theory of language of thought is a little like folk theory that a cold consists of a collection of sneezes, some of which escape. Does Fodor believe we must have a collection of sentences in our heads, just because some sentences come out of our mouths?

32. Dennett likes to make up possible erroneous folk theories to illustrate how a folk theory can seem obviously right to the folk, but yet be wrong. Dennett has another example of possible wrong folk theory: tiredness is caused by “fatigues” in the body. In this (fictional) culture, the way to say “I’m tired” translates literally to “I have fatigues”. Imagine a scientist trying to explain that they are wrong: Scientist: “There are no such things as fatigues” Folk: “You don’t believe in fatigues? Try running around the block a few times – then you’ll believe in fatigues!” Scientist: “I know what it is to have fatigues, but there are no such things as fatigues!” Note: the scientist wants to say “I know what it is to be tired”, but the only way to say that in this language is to say “I know what it is like to have fatigues.” Cognitive scientists have a similar problem when they try to say “I don’t believe there are beliefs.”

33. Dennett on Belief vs. Opinion Many beliefs are implicit beliefs. E.g. you believe: sheep are not ants sheep do not fly sheep do not dissolve in water etc. etc. etc. But have you ever thought about these things? So it is wrong to say that these beliefs are in the head. Belief is the propensity to agree with a statement or to act in a certain way.

34. Other beliefs are explicit. If you ask me if sheep are mammals and I answer, “yes, sheep are mammals”, this belief becomes an explicit belief. I am aware of this belief, and it is now represented in my head. Dennett calls implicit beliefs “beliefs” and explicit beliefs “opinions”. For Dennett, LOTH has a problem: only explicit beliefs (i.e. opinions) count as beliefs in LOTH, because only explicit beliefs are explicitly represented in the head. But most beliefs are implicit! So, LOTH is not an adequate theory of thought.

35. Midterm Quiz The midterm will be divided into two sections. In the first section, you will be given 5 words, and asked to define them, with examples when appropriate. Each definition in Section 1 will be worth 10 points. The 5 words will be chosen from the following terms: Undischarged homunculus Multiple realizability Informationally encapsulated The Language of Thought Hypothesis The causal theory of semantics The computational stance Supervenience Double dissociation Qualia Homuncular functionalism

36. Midterm Quiz (cont.) In the second section, you will be given 3 questions, and asked to answer 2. Each question will be worth 25 points. The questions will be chosen from the following: 1)What is the concept formation argument in favor of an innate mentalese? 2) Explain the systematicity and productivity parallels between thought and language. 3) Compare a functionalist definition of a mental state with an identity theory definition. What advantages pertain to the functionalist definition? 4) What characteristics make face recognition a good candidate for a modular function of the brain? 5) Why does Churchland maintain that folk psychology is a bad theory?