Mind in a physical world

Kim, Jaegwon, Mind in a Physical World.

This is one of the texts that JP Moreland uses in his Philosophy of Mind class.  Before I review the book and talk about why it is so important, perhaps some introductory remarks on the nature of the debate and terminology is in order.

Why it matters:  Until a few hundred years ago, even skeptics and atheists believed in a soul and a mind that wasn’t the same thing as the brain.  Now, the fashionable thing in academia is to either identify the brain with the mind or say that the mind is in some way “triggered” by physical events.  Neither of these latter two options are acceptable for Christians.

Dualism: in this context dualism simply means that the mind/soul and the body aren’t the same thing.  It doesn’t have the negative Kuyperian connotations that the body is bad.

Hard Physicalism:  This is the view that the mind and brain are the same thing.  Fewer scholars hold this view today since it is very untenable.

Weak Physicalism:  This view hesitates to say that the mind and brain are the same thing.  Rather, it says that all mental events have at their base a physical response.  Weak Physicalism means that the old-school hard scientism views lost the debate.  It also means, unfortunately for presuppositionalists, that the old Bahnsenian canard, “Have you ever stubbed your two on a law of logic?” simply doesn’t work any more.  Weak Physicalists, like Christian dualists, admit the existence of mental properties.

Where the Debate is Now:  There is a problem in philosophy of mind called “supervenience.”  On one level it seems commonsensical and one is hard-pressed to deny it.  On the other hand, it spells a number of insurmountable problems for physicalism.

The Review

Jaegwon Kim offers a weak physicalist discussion of supervenience and the difficulties it presents for current alternatives to Mind-Body dualism.  There is some technical language but it is kept at a minimum.  Of primary importance is Kim’s remarkably lucid discussion of “supervenience.”  

Supervenience tries to explain how mental properties and physical kinds, not tokens, are related. Mental properties supervene on physical properties: For any property M, if anything has M at time t, then there exists a physical base (subvenient) property P such that it has P at t, and necessarily anything that has P at  a time has M at that time (Kim 9).  This means “every mental property has a physical base that guarantees its instantiation” (10). Thus, mental properties supervene on physical properties.  The takeaway is that mental properties must always have a physical base.  This is an improvement on older materialist models which said mental properties were physical properties.  

Kim’s Larger Argument

P1: Either mind-body supervenience holds, or it fails.
P2: If M-B sup. fails, there is no way of understanding mental causation.
P3: Suppose M causes M* to be instantiated.
P4: M* necessarily has at least a physical base P*.
P5: M* is instantiated b/c M caused M*, but also because P* must be the subvenient base of M*.
P6: M caused M* by causing P*.
P7: Yet M also has a physical supervenient base P.
P8: P caused P*, and M supervenes on P and M* and M* supervenes on P*.
P9: The M-M* and M-P* causal relations are only apparent, and P really, really causes P*.
P10: If M-B sup. fails, then mental causation is incoherent.  If it holds, then it is also incoherent.

Supervenience presents a number of problems for physicalism, however.  What happens if mental property M causes another mental property M* to be instantiated? For example, my having the state “anger” causes me to have the mental state depression/fear/whatever.  This means that, if supervenience holds, M* must also have a physical property P* as its physical base.  Two problems immediately arise:

* It appears that a mental property (M) is causing a physical base (P*) which then launches M*.  Yet reductionists hold that all things have a physical cause.  But this raises the problem:

* So what causes M*?  It seems we have multiple causes, overdetermination.

Kim restates the problem:   if mental properties are physically irreducible and remain outside the physical domain, then, given that the physical domain is causally closed, how can they exercise causal powers (Kim 58)?


In terms of an introductory text, albeit a rigorous one, I highly recommend this book.  Admittedly, Kim doesn’t solve the problem (cf. p. 58), nor does he pretend to.  He introduces the reader to the relevant terminology and explains why certain moves available to physicalists cannot work.