Philosophy 4610

1. Philosophy 4610 Philosophy of Mind Week 3: Objections to Dualism Logical Behaviorism

2. Descartes: Mind and Body • So far, Descartes has argued that he exists as a thinking thingdefined by its capability of thinking, perceiving, and imagining. • He has also argued that, since God exists and is not a deceiver, there is reason to believe that the external world exists and is (more or less) how we perceive it to be. • In the Sixth Meditation, he now will consider how his mind (or thinking substance) is connected to his body (or extended substance)

3. Descartes: Mind and Body • Extension is the property of taking up space. If something has a size or a shape, it is “extended.” • According to Descartes, the body (like all bodies or objects) is extended but not thinking. The mind is thinking but not extended.

4. Descartes: Mind and Body • Descartes has two arguments for the real distinction between mind and body: • 1) The body can be separated from the mind, or the mind from the body. • 2) Mind is indivisible, whereas bodies are divisible: “For when I consider the mind, or myself in so far as I am merely a thinking thing, I am unable to distinguish any parts within myself … By contrast, there is no corporeal or extended thing that I can think of which in my thought I cannot easily divide into parts; and this very fact makes me understand that it is divisible.” (86)

5. Descartes and Dualism • According to Dualism, what is responsible for thinking and consciousness is not the brain (which takes up space and is physical) but rather the mind, which is not physical. The (physical) brain is closely connected with the (nonphysical) mind, but they are still different things.

6. Descartes and Dualism • According to Descartes, the eyes perceive objects and then focus the image on a central part of the brain. This part of the brain then “transmits” the information to the non-physical mind. The mind may then transmit back a signal telling the brain and body how to move or act.

7. Descartes and Dualism • Descartes thought this “transmission” of information from the physical brain to the non-physical mind and vice-versa worked through the pineal gland, a central part of our brains. • We now know that the pineal gland helps to regulate hormones in the brain as a whole.

8. Descartes vs. Modern Science: Dualism vs. Physicalism • Does Descartes’ story about the link between the physical and the non-physical make sense? • Does it involve a “miracle” that we can’t explain scientifically?

9. Descartes vs. Modern Science: Dualism vs. Physicalism • Some philosophers have described the view of modern science as “physicalism.” According to physicalism, everything that exists and that we are made up of is ultimately physical or material. There is the physical body, and the brain, but there is no additional non-physical mind or soul. • If physicalism is true, then all our thought, consciousness, and behavior can be explained in terms of the brain and nervous system. All that we are is our bodies and our brains.

10. Gilbert Ryle: “Descartes’ Myth” • Ryle (1900-1976) paid attention to the language that we use in describing our own mental states and events. • In his most famous book, The Concept of Mind, he argued that Descartes’ dualism is wrong and confused.

11. Ryle vs. the “Official Doctrine” • According to Ryle, Descartes formulated a dualistic picture of mind that has become the “official doctrine.” According to this doctrine: • “With the doubtful exceptions of idiots and infants in arms every human being has both a body and a mind. Some would prefer to say that every human being is both a body and a mind. His body and his mind are ordinarily harnessed together, but after the death of the body his mind may continue to exist and function.” (p. 32)

12. The Ghost in the Machine • Ryle also called the “official doctrine” of dualism the doctrine of the “Ghost in the Machine.” It treats human beings as if they consist of two parts: a mechanical body (that is essentially a machine) and a “spiritual” mind that has no physical existence (and so is like a “ghost”).

13. Problems with dualism: Other Minds • If dualism is true, then each person’s inner mental life is private -- known only to them. • If that’s the case, then how can I know that anyone else (besides myself) has a mind at all? • “Yet [dualism] presupposed that one person could in principle never recognize the difference between the rational and irrational utterances issuing from other bodies, since he could never get access to the postulated immaterial causes of some of the utterances. Save for the doubtful exception of himself, he could never tell the difference between a man and a robot.” (p. 37)

14. Ryle: Dualism is a ‘category mistake’ • According to Ryle, sometimes our ideas arise from a certain kind of mistake, what he called a “category mistake” • We would make such a mistake if, having seen a soccer match and all of the different players, we ask to see the “team spirit”

15. Ryle and category mistakes • We make a category mistake whenever we describe things that are actually on two different logical levels as if they were on the same level, and interacted with each other. • For Ryle, ‘the mind’ is just a way of describing the things that the person does (just as ‘team spirit’ is just a way of describing the things that the team does). Descartes’ mistake is to think of it as a thing that exists on the same level as the body and interacts with it.

16. Carnap: “Psychology in Physical Language” • Carnap (1891-1970) was a dedicated physicalist who believed that everything in the world is physical • He argues that we can take any sentence that seems to describe a mental experience or event and rewrite it in a completely physical language.

17. Carnap and Logical Behaviorism • Logical Behaviorism is the view that when we talk about “the mind,” we are really just talking about the behavior of the body (and hence about something that we can describe completely in physical terms. • For instance, we might translate, “Abner is angry” as: “Abner’s face is red; his fist is shaking; and he is yelling.” • How might we translate other “mentalistic” sentences?

18. Logical Behaviorism: objections • Logical behaviorism seems plausible for mental states that are always closely connected to behavior. But what about my mental state of thinking about the weekend or dreaming of a better future? • It seems clear that sometimes our behavior does not manifest our true mental states: for instance we may be acting, or covering up how we truly feel.

19. Logical behaviorism: dispositions • According to Carnap, at least some mental states are actually not actual behaviors but rather dispositions to behave. To say that I am thinking about the future is just to say that I would say “yes” if I were asked whether I was thinking about the future. • Just as a glass can be “fragile” even if it is not actually breaking, I can be in a certain mental state even if I am not actually exhibiting it right now.

20. Dualism and logical behaviorism: Summary • Descartes thought that mind and body were two completely separate substances, interacting through the pineal gland. • Ryle criticizes this view for failing to explain our knowledge of others’ minds and for giving an implausible picture of human beings as “ghosts in machines.” • Carnap’s physicalist picture – logical behaviorism – identifies the mind with outer, public behavior and with dispositions to behave.