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Philosophy of Mind: The Mind-Body Problem

Philosophy of Mind: The Mind-Body Problem. PHIL 101 – Fall 2009 Instructor : Daniel G. Jenkins. Review. We asked if and how the self persists over time. We discussed two broad positions on human nature that further illuminate the question: Essentialism Non-Essentialism. Essentialism.

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Philosophy of Mind: The Mind-Body Problem

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  1. Philosophy of Mind: • The Mind-Body Problem PHIL101 – Fall 2009 Instructor: Daniel G. Jenkins

  2. Review • We asked if and how the self persists over time. We discussed two broad positions on human nature that further illuminate the question: • Essentialism • Non-Essentialism

  3. Essentialism • The view that we have a core, soul, or essence that persists despite what we do or do not do. • Essentialism is attractive because it gives us a framework within which to say that we persist over time (and that even some aspect of us survives bodily death), and because it allows us to cope with failures. • Essentialism is problematic because we cannot identify one aspect of our core or essence that is both uniquely ours and that persists unchanged over time. Also, there is the problem of “non-paradigm humans,” and limits on freedom. • Some Essentialist Philosophers: Socrates, Plato, St. Augustine, Duns Scotus, Descartes

  4. Non-Essentialism • Non-essentialism: The view that we have no core, soul, or essence, but that we are what we do. Non-essentialism is attractive because it gives us a framework within which to argue that we can and do change over time and are not slavishly bound to our essence. It is problematic because it does not allow us to say that we survive bodily death, and because our failures are more meaningful in a view where we are defined by our actions. • Some Non-Essentialist Philosophers: Sartre, Nietzsche, Marx, Hume.

  5. Introduction to Philosophy of Mind • While essentialists have traditionally distinguished between body and soul and claimed that we are really the soul, Descartes distinguishes between mind and body on the basis that they have different properties. This gives rise to the mind-body problem and the dualist/physicalist debate.

  6. Objective of Presentation • To enable students to distinguish between the various theories of mind, the supporting arguments, and the relevant counter-arguments. • To have a productive and respectful dialogue about the nature of minds.

  7. What is the Philosophy of Mind? • The branch of philosophy that studies the nature of the mind, mental events, mental functions, mental properties, consciousness and their relationship to the physical body, particularly the brain.

  8. The Ontological Problem • What is the nature of mental states and mental properties? • Main solutions: • Dualism • Materialism

  9. But first, answer these questions: • How do you know you have a mind? • How do you know you have a brain? • How much does a thought weigh?

  10. What is Dualism? • Dualism is the view that the mind and body are ontologically distinct kinds of entities. • Dualists claim that minds are in some sense non-physical.

  11. Why Dualism? • Descartes argued that mind and body are distinct because they have different properties, namely that the mind is immaterial, infinite, and unextended, while the body is finite, extended, and material. • Descartes thinks these properties are manifestly evident, and uses a variant of what philosophers call Leibniz’ Law, or the Identity of Indiscernibles to argue that therefore the mind and body are separate things.

  12. Leibniz’ Law/Identity of Indiscernibles • According to this principle, if two objects have in common all of their properties they are identical. • Descartes applies the principle to argue that because the mind and the body do not have all their properties in common, they are not the same thing.

  13. Types of Dualism: • Substance Dualism The mind is an independently existing non-physical substance. • Cartesian Substance Dualism: • Res cogitans: Non-physical thinking substance • What is distinctive of the mind is that it is a thinking thing. • Res extensa: Physical extended substance • What is distinctive of the body is that it is spatially extended. 2) Popular Substance Dualism: • Similar to Cartesian substance dualism, but the mind is believed to be spatially located somewhere inside the head.

  14. Types of Dualism: • Property Dualism • The mind is a group of non-physical properties that emerge from the brain, but cannot be reduced to it. • The mind is not a separate substance from the brain, but rather is an emergent property that requires the brain to exist. • These non-physical properties can never be adequately explained by any physical theory.

  15. Arguments in Support of Dualism • Religion • Introspection • Irreducibility

  16. Arguments in Support of Dualism: Religion • Most religions believe in the existence of an immortal soul that survives the death of the body. • For this to make sense substance dualism must be true.

  17. Arguments in Support of Dualism: Religion • Objection: • “Social forces are the primary determinants of religious beliefs for people in general. To decide scientific questions by appeal to religious orthodoxy would… put social forces in place of empirical evidence.”

  18. Arguments in Support of Dualism: Introspection • I don’t experience myself as a physical system, but rather as a mind that believes, fears, desires, and has qualia (i.e. raw feeling). • Direct introspection reveals to me that I am a thinking thing, not merely a physical thing.

  19. Inasmuch as thoughts, beliefs, desires, and willings are things that exist, and inasmuch as the fundamental basis of their existence is our experience of them, any attempt to explain qualia by reducing them to non-experiential things is bound to omit something important. • Attempts to reducequalia to physical things, like neurons or electro-chemical brain states, maintain that our experiences are not experiences at all but are “really just” a special kind of organization of matter. • This denies the empirically evident fact of our conscious experience.

  20. Mary’s Black and White Room • Contemporary philosopher David Chalmers argues just this when he gives us the thought experiment of the neuroscientist raised in a black and white room. • Mary, having never seen color, has accrued omniscient knowledge of neuroscience, physiology and anatomy necessary for understanding human color perception. • If she leaves the black and white room and sees a red object for the very first time, will she learn something new? • Chalmers argues that she will.

  21. To reiterate… • Dualists today, not unlike Descartes in the 17th century, maintain that the mind is not identical to the brain.

  22. Churchland’s Objections to the Argument from Introspection • It is a mistake to assume that introspection reveals things as they really are, in their innermost nature. • Scientific progress has yielded very counter-intuitive results concerning all other types of phenomena, and it seems very likely the correct theory of mind will be highly counter-intuitive as well. • Also, if it is true that one’s mental states are identical to physical states (i.e. materialism), that information would not be accessible through introspection alone.

  23. But perhaps Churchland is making a straw man of the dualist position… A straw man argument is an informal fallacy based on misrepresentation of an opponent’s position. To "attack a straw man" is to create the illusion of having refuted a proposition by substituting a superficially similar proposition (the "straw man"), and refuting it, without ever having actually refuted the original position

  24. Churchland’s objection might not be to the Argument from Introspection, but to some misrepresentation of it. One can argue that introspection reveals thoughts whose existence – as thoughts – is manifestly evident, and that acknowledging the existence of thoughts asserts nothing about “how things really are in their innermost nature.” • Similarly, physicalism can be criticized for claiming to explain “how things really are;” it is unclear that we ought to give primacy to the physical merely because it is physical.

  25. That is, if we are interested in our experiences qua experiences, how will a physical account explain their “innermost nature?” • A physicalist account might trump dualism in explanatory power and thus settle the matter, but the explanatory power of physicalism is overrated. Churchland asserts that one day neuroscience will explain and predict human behavior more effectively than the dualist’s language of willing, intending, feeling, and so forth. • However, physicalism does not do so today. Hence it does not reveal things “in their innermost nature.”

  26. Arguments in Support of Dualism: Irreducibility • It seems unimaginable that a purely physical system could ever use: • Language • Mathematical reasoning • Construct new concepts • Learn/Remember • Understand space and time • Know what it is like to smell a rose • Etc.

  27. Arguments in Support of Dualism: Irreducibility • Objections: • Development of calculators, computer languages, ANN, etc. • These innovations invade areas of the mind that past dualistic philosophers saw as forever closed to mere physical devices. • One shouldn’t mistake a failure of imagination as an insight into necessity.

  28. Arguments in Support of Dualism: Free Will • Although Churchland does not address this issue directly, and though we will treat this issue in greater detail later, it is worth mentioning now. • If the mind is reduced to the brain, a physical thing, then we are dealing with a causally closed system in which human beings do not make actual choices. This is inconsistent with our experience as free beings.

  29. Objections to Free Will From Compatibilists • It is possible to be determined yet conceive of oneself as a free being. • “The world could be deterministic on odd days of the week and indeterministic on even days and we would never know the difference.” – Daniel Dennett

  30. Objection from Hard Determinists • Free will does not exist. Every thought we have, and every action we take, was guaranteed to happen given the physical state of the universe at the big bang.

  31. Objection from Materialists • While materialism doesn’t necessarily entail hard determinism, the objections someone like Churchland might voice to the argument from free will might look a lot like the objections he gives to the argument from introspection: our intuitive account of free will may have to be revised in light of scientific findings; our experience of free will might not line up with the facts of free will.

  32. This objection must be taken seriously. Our sense that we have free will is something about which we can be mistaken. • The point is that if we have free will, we need dualism to posit the interruption in the chain of physical causation required for free choices (choices not guaranteed to be made by previous physical states of the universe. • Inasmuch as we are interested in giving an account of free will that jibes with our intuitions that we are free beings, we are interested in defending dualism.

  33. Arguments Against Dualism 1) The Interaction, or “Mind-Body” Problem • Descartes vs. Princess Elizabeth • The Pairing Problem 2) Ockham’s Razor 3) Evolutionary History 4) Explanatory Impotence

  34. Descartes vs. Princess Elizabeth • In his writings, Descartes identifies the pineal gland as the location where mind-body interaction occurs. • He states: • “The activity of the soul consists entirely in the fact that simply by willing something it brings it about that the little gland to which it is closely joined moves in the manner required to produce the effect corresponding to this desire.” • The causal effect of the mind on the pineal gland, in turn, affects the animal spirits, which pass along the paths of bodily fluids in the body and bring about movement.

  35. Descartes vs. Princess Elizabeth • Princess Elizabeth (a pupil of Descartes) wrote him a letter asking him to explain: • “How the mind of a human being, being only a thinking substance, can determine the bodily spirits in producing bodily actions.” • In other words, how can a non-physical thing have a causal effect on a physical thing?

  36. Descartes vs. Princess Elizabeth • Descartes replied with: • “I observe that there are in us certain primitive notions which are, as it were the originals on the pattern of which we form all of our other thoughts… As regards the mind and body together, we have only the primitive notion of their union.”

  37. Descartes vs. Princess Elizabeth • To which Elizabeth replied: • “It would be easier for me to concede matter and extension to the mind than it would be for me to concede the capacity to move a body and be moved by one to an immaterial thing.”

  38. Arguments Against Dualism: • The Interaction Problem • How do non-physical and physical substances interact? • Causal closure of physical systems (i.e. conservation of momentum and energy) • Most contemporary philosophers now believe that an immaterial entity (if it existed) could not affect the material world (or other immaterial entities). ????????

  39. Arguments Against Dualism: The Interaction Problem Which gun caused which death? How do we know that?

  40. Arguments Against Dualism: The Interaction Problem • The reason why we select one gun over the other is because of the causal chain between the objects in space. • However, the immaterial isnot spatially extended, and therefore cannot enter into causal relationships.

  41. Arguments Against Dualism: The Interaction Problem • For example, which mind caused the brain’s neurons to fire? How could we tell?

  42. But this is less of a problem for the property dualist… • The mind might be an emergent property of the brain without being identical to it. • The mind might also have no control over the brain, and hence we have nothing to explain (though part of the desire to argue for dualism stems from the desire to argue for human freedom; unless the mind controls the brain, and thus the body, we are not free in the way we commonly use the term).

  43. Which Trade-Off ? • Perhaps it comes down to determining which theory poses greater problems, determining which problems are insurmountable and which problems we can live with. • That is, finding out how great a problem the mind-body problem is will come into sharper focus when we discuss materialism.

  44. Arguments Against Dualism: • Ockham’s Razor • Ockham’s Razor states: • “Do not multiply entities beyond necessity.” • If it is possible to account for mental phenomena without supposing the existence of non-physical substances or properties, then the simpler theory is to be preferred.

  45. Dualist Reply: • At present, accounts of the mind have greater explanatory power concerning many complex behaviors than neuroscience is able to provide. • We cannot look at the brain and “see” complex thoughts or predict complex behavior on the basis of such observations. • Reference to a person’s mind is more effective in explaining and predicting behavior, and assertions that neuroscience will one day be able to supercede this explanatory power are dogmatic.

  46. For example: • http://www.youtube.com/watch?v=8jc8URRxPIg

  47. Arguments Against Dualism: • Evolutionary History • The evolutionary narrative provided by the sciences is a purely physical story. • If this is the case, then at what point did this non-physical mind arise? • Similarly, at what point does this non-physical mind enter a developing fetus?

  48. Dualist Reply: • Evolutionary history is not a purely physical story. Property dualism is consistent with natural selection of physical properties that correlate with desirable or advantageous mental properties.

  49. Arguments Against Dualism: • Explanatory Impotence • The neural dependence of all known mental phenomena, and the progress made in the neurosciences shows the effectiveness of the materialist research program. • Whereas, the dualists can hardly tell us anything about the non-physical substance/properties. • “Compared to the rich resources and explanatory successes of current materialism, dualism is less a theory of mind than it is an empty space waiting for a genuine theory of mind to be put in it.” • Furthermore, the dualist’s appeal to the non-physical merely pushes the question back a step (i.e. How do mental states adhere in this non-physical substance?)

  50. Dualist Reply: • Again, the dualist may not be able to describe non-physical properties, but reference to the mind is more effective than reference to the brain in explaining and predicting many behaviors. • In other words, in pressing the dualist to explain non-physical properties rather than consult qualia to explain behavior , the materialist might be missing the point.

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