Minds=Brains

1. Minds=Brains

2. Before We Begin Counseling and Psychological Services (CAPS): • caps.sa.ucsb.edu • counseling.ucsb.edu • (805) 893-4411

3. Announcements • The paper due date is postponed until Friday June 6th. • Attendance will not be taken at sections this week (though they will be held). • Office hours will be held as usual this week. • I will hold extra office hours after lecture on Friday.

4. Physicalism The main problem for dualism was that it could not account for the interaction between immaterial and material objects.

5. Physicalism Roughly, this was because minds and physical bodies were claimed to be so radically different that they could not interact.

6. Physicalism This problem can be easily avoided by a view which claims that minds are physical things with physical properties. Physicalism: Every mental event is a physical event.

7. Physicalism Given the close association of our brains to our mental lives, it is natural to suppose that mental states and events just are states of our brains.

8. Brain Identity Theory Brain identity theory claims that every mental state is identical to a physical state of some brain. For instance: Pain=C-fibers firing.

9. Brain Identity Theory According this claim is analogous to other sorts of scientific identity claims: • Lightning=atmospheric electric discharge • Heat=mean molecular motion

10. Brain Identity Theory Just as heat is nothing over and above mean molecular motion, pain is nothing over and above C-fibers firing. Pain and the firing of C-fibers are one and the same thing.

11. Brain Identity Theory In general, the claim that mental states are brain states seems to have an air of scientific respectability. • Avoids positing “spooky” talk of minds or souls. • Keeps everything firmly in the realm of the physical. • Has the result that we can study minds by studying the nature of brains.

12. Brain Identity Theory “It seems to me that science is increasingly giving us a viewpoint whereby organisms are able to be seen as physico-chemical mechanisms: it seems that even the behavior of man himself will one day be explicable in mechanistic terms. There does seem to be, so far as science is concerned, nothing in the world but increasingly complex arrangements of physical constituents…

13. Brain Identity Theory Except for one place: in consciousness. That is, for a full description of what is going on in a man, you would have to mention not only the physical processes in his tissue, glands, and nervous system, and so forth, but also his states of consciousness: his visual, auditory, and tactual sensations, his aches and pains…I just cannot believe that this can be so. That everything should be explicable in terms of physics, except the occurrence of sensations seems to me to be frankly unbelievable.” (Smart)

14. The Unity of Science This may sound like a blind statement of faith (Smart acknowledges this) but think how weird the world would be if: • The laws of physics could successfully explain everything except minds. • Biology could explain everything having to do with life, except minds. • Some of the basic laws of the universe had to do with ridiculously complicated things like minds.

15. The Unity of Science Recall Dawkins’ assertions about complexity. If minds cannot be reduced to simpler entities and explained scientifically, we would be left with an extraordinary unexplained level of complexity in the universe.

16. The Unity of Science The brain identity theory is especially plausible if one endorses something like: The Unity of Science: Every observable phenomena can ultimately be explained in terms of some set of fundamental physical laws.

17. Unity of Science

18. Unity of Science Adopting the brain identity theory gives us an easy way to fit the mind into this picture. The nature of minds are to be explained by studying the neurophysiological, biological, and chemical nature of brains.

19. Brain Identity Theory Brain Identity theory seems to have a lot going for it: • It can easily accommodate interactionism (minds are brains, which are physical things) • It fits nicely into a scientific worldview. • It allows for the empirical study of minds.

20. Brain Identity Theory Smart raises and answers a series of objections to this seemingly plausible proposal.

21. First Objection An illiterate medieval peasant knew all about pain, but didn’t know anything about C-fibers. So pain is not identical to C-fibers firing.

22. First Objection Response: • You could just as well say that heat is not identical to mean molecular motion because peasants didn’t know anything about molecules! • The brain identity theory does not say that the concepts of pain and C-fibers are the same. • Just because someone has two different concepts for something doesn’t entail that it is two different things (e.g. Clark Kent/Superman)

23. First Objection A related objection could try to point out that the meanings of our words “pain” and C-fibers” are different, but this makes the same sort of error.

24. Second Objection • The pain is in my arm. • The C-fibers are firing in my head. • Therefore, the pain is not identical to the firing of the C-fibers. (by Leibniz’ law)

25. Second Objection Response: • Strictly speaking, the damage is in you arm. The pain is in your head. • Phantom pains in amputated limbs • Dream pains • Pain produced by exciting C-fibers in the brain

26. Second Objection Consider an analogous case: my visual experience of the book on the table: • I have an experience as of a book right there. • But no one would be inclined to say that my visual experience itself is on the table. • Why not say the same thing about pain?

27. Third Objection Pains and C-fiber firings don’t share other kinds of properties, for instance: • Pains can be sharp or dull. • C-fiber firings cannot be sharp or dull. • Therefore, pains are not identical to C-fiber firings.

28. Third Objection This seemingly begs the question. If brain identity theory is true, strange as it may sound to say: • When my C-fibers are firing, it can feel sharp or dull to me.

29. Third Objection The oddness of such claims is due to the fact that our concepts of pain and C-fibers differ, but we already shows that this does not bear against the brain identity theory.

30. Fourth Objection • Pains, like all mental states are private (in some special way). • C-fiber firings are not private in this way. • Anyone can detect them using MRIs and FMRIs. • So pains are not identical to C-fiber firings.

31. Fourth Objection Responses: • Before people had MRIs and FMRIs there wasn’t any way to tell directly whether someone’s C-fibers were firing. Now we have this technology. • But people don’t carry these things around with them, so whether or not you are in pain is still private in any practical sense.

32. Fourth Objection More importantly, even if people did carry around such devices, they wouldn’t know about your pain in the same way. So even according to brain identity theory, you can still have a special kind of access to your pain that others don’t.

33. More Serious Problems Smart does a fair job of addressing a set of initial worries for the brain identity theory. But there are serious problems on the horizon.

34. Announcements Finish reading the Kim selection. The due date on the paper has been postponed until next Friday. Both Dillon and I are holding extra office hours today after lecture. Savannah Okey see me now or after lecture.

35. More Serious Problems Before proceeding, we need to get a bit clearer on the nature of the theory we are criticizing.

36. Tokens and Types When Smart says that all mental states are brain states he could be referring to tokens of such states or types of such states.

37. Tokens and Types How many letters are there in the following word: Mississippi There are two correct answers: • 11 (11 letters of any kind) • 4 (4 types of letter: “M”, “I”, “S”, “P”)

38. Tokens and Types A token is a particular thing. A type is a kind of thing.

39. Tokens vs. Types Using this distinction we can distinguish two different physicalist claims: • Token Physicalism • Type Physicalism

40. Token Physicalism Token Physicalism: Every particular mental event is identical to some physical event or other.

41. Token Physicalism Token physicalism is a very weak thesis. For all it says, pain in one case could be C-fibers firing, but later on, pain could be D-fibers or some other neural event.

42. Type Physicalism By making claims such as: “pain=C-fibers firing” brain identity theorists like Smart clearly mean something stronger than this. What they want to say is that every instance of pain, is an instance of C-fiber firing.

43. Type Physicalism So brain identity theory is a version of: Type Physicalism: Every mental event type is identical to a physical event type.

44. Type Physicalism This is a much stronger claim. To show that brain identity theory is false all we need are possible cases in which you have a pain but you lack C-fibers.

45. Objections to Brain Identity Theory • Modal objection • Multiple realizability • The problem of consciousness

46. Background on Possibility When philosophers talk about modality they are usually talking about a domain of metaphysics having to do with possibility and necessity.

47. Background on Possibility Possible World: A way the world might have been that settles every question of fact (for any claim p, either p or not-p is true).

48. Background on Possibility p is necessary if and only if p is true in every possible world. Necessary truths could not have been false no matter how the world might have been: e.g. 2+2=4.

49. Background on Possibility p is possible if and only if, there is at least one possible world where p is true. There is a way the world might have been such that p would have been true.

50. Background on Possibility For example: So there is a possible world in which I wore a red shirt today. There is no possible world in which I (Tim Butzer) was a rock.