Tuesday, November 13, 2007

building blocks

It's sometimes argued by substance dualists that you can't move from mindless material constituents to a mind formed purely of matter; dualists see mind as substantially different from matter-- res cogitans and not res extensa. Forgetting for a moment the anti-physicalist prejudices that may or may not fuel such an argument, I'll note that this dualistic contention is at least partly rooted in the fallacy of composition. This fallacy involves drawing the wrong conclusion about the whole based on the properties of its parts. The example I remember from one book said something like this:

1. All the machine's parts are green, therefore the machine is green.
2. All the machine's parts weigh 1 pound, therefore the machine weighs 1 pound.


Obviously, something is wrong. In sentence (1), we are able to conclude something about the whole based on its parts, but are unable to do this with (2), despite the use of the same reasoning. The fallacy of composition is a strong caution against intuiting something about the whole based on its parts precisely because incorrect statements like (2) are possible.

Substance dualists, reasoning from parts to the whole, seem intent on saying:

All the parts of the brain are devoid of mind, therefore the brain itself is devoid of mind.

Because dualists do believe mind exists, they conclude that mind must somehow be separate from the material brain. Every once in a while, however, a science article comes along that reaffirms the fact that large aggregates of biotic and abiotic matter can, when properly configured, exhibit emergent properties and behaviors, to wit:

"No matter how much you look at an individual army ant," Dr. Couzin said, "you will never get a sense that when you put 1.5 million of them together, they form these bridges and columns. You just cannot know that."

The above quote is a reminder to substance dualists that arguing from parts to the whole is effectless if the point is to establish that matter simply cannot amount to mind.


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1 comment:

Malcolm Pollack said...

Good post, Kevin. Clear and simple.