A quick list of some of the relevant issues and arguments we have considered. Most have been discussed in class; others are in the readings but have not been discussed much in class. This is just meant to be a starting point for your study. I don't pretend that this handout lists all the important arguments, and for those it does list, it certainly doesn't contain a full enough description to enable you to do well on the midterm!
 

The first several topics we examined were various responses to the mind-body problem, i.e. various views about the ontological nature of mental states.

What is it?

Substance dualism is the view that there are two radically different kinds of substances: mental substances, which have no physical properties at all (e.g. no mass, no location in space, etc.), and physical substances, which have no mental properties at all (no thoughts, no conscious experience, etc.). Ryle does a nice job of elaborating this view prior to his critique of it.

Versions and Articles

Descartes: interactionist dualism. (Physical events can cause mental ones and vice versa.) Criticized by Ryle.

Huxley: epiphenomenalism. (Physical events can cause mental ones, but not vice versa.) Criticized by Smullyan (indirectly).

Arguments for Dualism

1. Descartes, Med. 6: I can clearly and distinctly conceive mind without conceiving body, and vice versa; therefore God could make one without making the other; therefore they are distinct even if closely linked. [See Chalmers, p. 16, column 1.]

2. Descartes, Med. 6: body is divisible, mind is not divisible, therefore body must be distinct from mind. [See Chalmers, p. 18, bottom of column 2.]

Arguments against Dualism

1. category-mistake (Ryle)

2. if dualism were true, the problem of other minds would be insoluble. But we have no problem determining that other people have minds. Therefore dualism is false. (Malcolm)

3. mysterious how mind could have any causal effect on body if dualism were true. (Could be construed to be an argument for epiphenomenalism rather than against dualism in general.)
 

What is it?

In class, I distinguished between a linguistic thesis, a methodological thesis, and a metaphysical thesis. The most basic of these is the metaphysical thesis. This says that to be in a mental state of a certain type (e.g. pain) is to behave in certain ways (e.g. wincing, moaning, etc.), or, in more sophisticated versions, to have a disposition to behave in certain ways.

(The linguistic thesis says that terms for mental states mean the same as, or can be defined in terms of, terms for behaviors or dispositions to behave. The methodological thesis says that psychology should not depend on hypotheses about "internal" mental states. See this handout for more.)

Articles

Behaviorism is defended by Carnap. (However, he focuses on the linguistic thesis rather than on the metaphysical thesis.) It is criticized by Putnam in "Brains and Behavior." (Putnam's essay "The Nature of Mental States," and Block's essay "Troubles with Functionalism," also criticize behaviorism in passing.)

Arguments for Behaviorism

1. Linguistic argument: consider how we learn words for mental states like pain. We learn to apply them by associating them with publicly observable behaviors. So the criterion for applying such a term involves behavior. So the meaning of the term is given by a set of behaviors. But if 'pain' means a set of behaviors, then pain = a set of behaviors. (one line of response: distinguish verification conditions from truth conditions.)

2. Epistemological argument: we must be able to conclusively verify any scientific hypothesis; we can't conclusively verify hypotheses about inner states; so scientific psychology can't refer to inner states. This is, roughly speaking, Carnap's argument: notice that he thinks the only alternative to behaviorism is "the error of a hypostatization as a result of which a remarkable duplication occurs: besides or behind a state of affairs whose existence is empirically determinable, another, parallel entity is assumed, whose existence is not determinable" (Chalmers, p. 44, my emphasis). (Note Putnam's response that this kind of argument rests on an overly simple account of how theories are verified: see his section on "Some Behaviourist Arguments," pp. 50ff.)

Arguments against Behaviorism

1. Evidence that any psychological theory complex enough to predict human behavior will need to invoke internal states. (Compare the problem of predicting a computer's output on the basis of its input: hopeless without an account of what's going on in between. Surely humans are at least this complex.)

2. possibility of mental state without associated behavior (Putnam's "super-Spartans").

3. possibility of behavior normally accompanying a mental state without the presence of the state (acting; this is the converse of 2). This is related to Block's suggestion that "behaviorism is guilty of liberalism -- ascribing mental properties to things that do not in fact have them" (Chalmers p. 95).

4. dispositional version of behaviorism seems to either be circular or involve an infinite regress. believing that today is Monday is the state such that if I am in it, and I want to tell the truth when it won't harm me, and I believe that it won't harm me to tell the truth about what day I think it is, and . . . then if someone asks me "Is today Monday?" I will say "yes." But this definition appeals to desires and beliefs which will also need to be behavioristically defined, and their definitions will appeal to still further beliefs and desires. It seems unlikely that there's any way to give these definitions without circularity or regress.
 

What is it?

The view that mental states (or at least some of them, notably qualia, "raw feels," conscious experiences) are identical with neurophysiological states.

Articles

The Identity Theory is defended by Place, Smart, and Feigl. We didn't read an essay which was only a critique of the identity theory, but Putnam's article "The Nature of Mental States" includes a critique of the identity theory along with his defense of functionalism.

Arguments for the Identity Theory

1. correlations between brain states and mental states. Simplest explanation is that they are really the same. (Place: the identities involve the "is of composition": we contingently discover these identities in the same way that we discovered that heat = molecular motion or lightning = electrical discharge.) Note that there appear to be two components to this argument: (a) empirical evidence for correlations between brain states and mental states, and (b) an appeal to simplicity in order to reject the possibility that these correlations are between radically different things. On (b) compare J.J.C. Smart on Occam's Razor at the beginning of his essay, and his discussion of "parsimony and simplicity" at the end of his essay.

Arguments against the Identity Theory

1. Species chauvinism: the identity theory inappropriately requires that any creature with mental states must have a central nervous system like ours. This use of the term "chauvinism" is due to Block: see Chalmers, p. 95. Unfortunately, Block confusingly calls the identity theory "physicalism." Compare Putnam on octopus pain in section III of "The Nature of Mental States."
 

What is it?

In a nutshell, the idea that mental states are functional states analyzable in terms of inputs, outputs, and relations to other mental states. For lots more, see my detailed handout on functionalism.

Articles

Functionalism is explained and defended by Putnam in "The Nature of Mental States." (And also by Armstrong in "The Causal Theory of the Mind," but we didn't discuss this much and I won't expect you to be familiar with it for the midterm.) It is criticized by Block in "Troubles with Functionalism" and by Nida-Rumelin in "Pseudonormal Vision."

Arguments for Functionalism

1. Less liberal than behaviorism in attributing mental states, because it takes internal states seriously. (Not so much an argument as an advantage; that functionalism doesn't share a failing of behaviorism is not necessarily a positive reason to think that it is true!)

2. Less chauvinistic than the identity theory: allows that mental states may be implemented by nonhuman creatures. (Again, not an argument so much as an advantage.)

3. In principle, we could represent human sensory inputs, behavioral outputs, and relations between internal states in a giant "machine table" of the same sort used for Turing machines. Such a machine table constitutes a functional definition of internal states (just as the machine table of a Turing machine gives a functional definition of the TM's states). Human mental states correspond to the internal states defined by the "machine table." So human mental states are functional states. (Something along these lines seems to be Putnam's positive argument for functionalism.)

4. Common-sense psychology implicitly defines human mental states in terms of inputs, outputs, and relations to other mental states. So if common-sense psychology is true, then mental states are functional states. (We talked about this kind of argument a little in class, and it is discussed at length in my functionalism web page, but we didn't read the most important defense of this argument, namely David Lewis's essay "Psychophysical and Theoretical Identifications," which is, however, included in Chalmers.)

Arguments against Functionalism

1. Absent Qualia argument. (Block develops a version of this by means of his homunculi-headed robot example.)

2. Inverted Qualia argument. (Nida-Rumelin develops a version of this argument.)
 

The Main Idea

The relation between the Identity Theory and Functionalism is one example of a larger set of issues about what Fodor calls the "special sciences," i.e. sciences that are less general and in a sense at a higher level of abstraction than physics. The Identity Theory is a reductionist theory, while Functionalism apparently is not. Fodor argues that not only in psychology but also in the other special sciences, we should reject reductionism in favor of theories that allow the properties of the special sciences to be multiply realized.

Articles

Fodor, "Special Sciences," and Kim, "Multiple Realization and the Metaphysics of Reduction."
 

The following topics are interesting in their own right, but also pose potential problems for materialist theories.
 

The Main Idea

The problem of how mental events could cause physical events has traditionally been a problem for dualist theories (ever since Princess Elizabeth raised this as a problem in correspondence with Descartes). Kim suggests that nonreductionist physicalism (of the kind defended by Fodor) may also face a problem in explaining how mental events can cause physical events.

Articles

Kim, "The Many Problems of Mental Causation," and Yablo, "Mental Causation."

Three Problems of Mental Causation

1. The problem of anomalous mental properties.

1. There are no exceptionless laws involving psychological notions.
2. If event e1 causes event e2, then there must be an exceptionless law connecting events of the same type as e1 with events of the same type as e2. (The "nomological requirement on causation.")
3. If e1 causes e2 because e1 is of mental type M, then the law connecting e1 and e2 must involve events of type M. (That is, the "events of the same type as e1" mentioned in premise 2 must be events of type M.)
Therefore,
4. Mental events do not cause physical events because of the kind of mental event they are.

2. The problem of intrinsic mental properties.

1. The semantic properties of mental states (i.e. what they are about) are not intrinsic. (They depend on facts about the individual's history and environment.)
2. What an event causes depends only on the current, intrinsic properties of the event.
Therefore,
3. Mental events do not cause other events by virtue of their semantic properties. (So, for instance, the content of my beliefs does not play a role in determining what they cause.)

3. The problem of causal exclusion.

Consider a case in which a mental event m of type M causes a physical event p. (Note that lower-case letters represent events, upper-case letters represent types or properties.)
1. p has a complete physical cause c. (causal closure of the physical)
2. c causes its effect by virtue of its physical type C.
3. Even if m = c,  M ≠ C. (This follows from nonreductionist physicalism, e.g. functionalism.)
Therefore,
m does not cause p by virtue of its mental type M.

A Response to the Exclusion Problem

Yablo: physical events are determinates of mental determinables. That is, the relation between a mental property and its physical realizers is like the relation between red and its determinates such as scarlet, crimson, or like the relation between drinking and its determinates such as guzzling, sipping, etc.

Then there should be a similar exclusion problem for other determinate/determinable pairs. For example, since the property of guzzling the hemlock is sufficient to ensure his death, it seems that this would exclude the property of drinking the hemlock from being responsible for his death. But that seems nuts.

Yablo argues two things: 1. a determinable and its determinate on a particular occasion can both be causally relevant to an effect: causal relevance of the determinate does not exclude causal relevance of the determinable. 2. It may be that we can't regard both of them as being "the cause" of the effect. But here the determinable may have a better claim in some cases than its determinate. The cause of an effect is such that, if it had not occurred, the effect would not have occurred either. Socrates' guzzling the hemlock does not have this property (since if he had not guzzled it, he would have drunk it in some other way, still resulting in his death). His drinking the hemlock, however, does have this property. So the drinking is a better candidate to be the cause than the guzzling.

[note to myself: I should be a little more careful about the distinction between two ways of describing these issues. Kim treats token events m and c as being identical (m = c), but talks about events causing effects by virtue of properties, so the exclusion is an exclusion of property M by property C. Yablo starts off talking about properties, but then argues that the events themselves are distinct. My last two sentences above presuppose this view, and really should be reformulated to make them compatible with Kim's way of describing the situation. But it's hard to do that without some pretty awkward formulations.]
 

The Main Idea

Does consciousness pose a special problem for materialist theories? How can a materialist theory account for it?

Articles

Nagel's bat essay suggests that consciousness does pose a problem for materialist theories. His argument is a version of what has since come to be known as "the knowledge argument."

Block simply distinguishes between several different things that could be meant by "consciousness."

Dennett gives a materialist reply to worries about conscious experience (qualia). His reply is essentially eliminativist: qualia don't pose a special problem for materialism because there are no such things.

Chalmers gives a nice overview of various consciousness-based arguments against materialism and possible materialist responses. (Chalmers himself is a property dualist.)

Types of Consciousness

Block's main distinction is between phenomenal consciousness ("P-consciousness") and access consciousness ("A-consciousness"). The former involves having qualia or raw feels. The latter is defined in information-processing terms; for a state to be conscious in this sense is for it to be available for use in cognitive tasks such as reasoning and reporting. (So, very very crudely, a state is A-conscious if I can tell you I'm in it.)

Arguments

The knowledge argument (roughly the argument of Nagel's "Bat" essay): I can know all there is about the physical makeup and functioning of bats without knowing what it is like to be one. So knowing all the physical facts does not suffice for knowing the facts about conscious experience. So the facts about conscious experience are not physical facts.

One response: eliminativism about qualia (Dennett). Dennett's argument is basically to argue that supposing that there are qualia leads us to think that there are facts that there is no conceivable way to discover. But that's nonsensical (verificationism), therefore there are no qualia. (Dennett insists that he is not denying that there is conscious experience; he is just denying the philosopher's interpretation of conscious experience as involving qualia. We might say that he is denying that there is a real distinction between P-consciousness and A-consciousness.)