Friday, April 23, 2010

Electrons R Us!

An imaginary scenario of NASA headquarters as a new robotic Mars rover begins its mission on the surface of that planet: Evelyn, the software engineer who wrote the code that allows the rover to pick its way across the Martian surface without running into rocks and cliffs, has invited her philosopher friend, Pete, to watch the rover's progress. Evelyn exults as the rover successfully negotiates one obstacle after another, and brags to Pete about how well her control program is working. Pete, however, complains, "It's not your program that controlling the rover; it's just electrons in those electronic circuits following the laws of physics!"

At this point, I can only imagine Evelyn standing there agape, thinking of the years she spent developing that software, unable to come up with any kind of non-insulting reply.

Pete is guilty of level confusion: his objection amounts to the claim that if a physical description of the rover at the level of electrons is correct, then any other description of the rover's behavior must be incorrect. I think the free will deniers are guilty of the same thing.

(Note: I am not making the claim that human brains are like computers in any particular way. I am only proposing the rover story as an analogy to help us understand different levels of description.)

Let's recall Argument #2 from this post:

Argument #2 - Causal Determinism is a Necessary Condition
for Moral Responsibility
Premise 1: Unless there are extenuating circumstances, persons are (to be) held morally responsible for their actions.
Premise 2: Being unable reasonably to have foreseen the consequences of their actions is one such extenuating circumstance. (Recall that young children who cannot reasonably foresee the consequences of their actions are not to be held morally responsible for the consequences.)
Premise 3: In order to be able to anticipate or foresee the likely (or even the remotely likely) consequences of one's actions, the world must not be random, i.e. the world must be fairly regular (or causally determined).

Thus: Moral responsibility requires that there be causal determinism.

This argument, I think, is sound. In order for there to be moral responsibility, I want my actions to be causally determined. Determined by what? By me, of course! But what am I? I am my thoughts, feelings, desires, beliefs, and so forth. But if we are right in assuming that the mind is a purely physical entity (no magic allowed!), then thoughts, desires, etc., are all the results of some sort of electro-chemical activity in my brain.. ("We are electrons, and electrons are us.") And if my actions are to be determined by my thoughts and desires, then they ought to be determined by those patterns of electrical activity that are the physical counterpart of those thoughts and desires.

So if free-will deniers claim that we can't do other than what we did because "it's all just electrons" following the mindless laws of physics, they are committing the same sort of level confusion as Pete.

There can be a low-level description of an action that consists of electrons following physical laws. And there can be a high-level description of the same action that consists of mental states like thoughts and desires. And there need not be any contradiction between the two descriptions, any more than there is a contradiction between the electron-level description and the program-level description of the rover. At the physical level, all we see is electrons affecting the motion of other electrons. But at the mental level, we have desires affecting thoughts, thoughts influencing desires, and, crucially, a mind capable of reflecting on its own mental state.

Free will is something that exists at the mental level; it is a characteristic of the relationship between thoughts and actions. To try to look for it at the level of electrons is to commit a category error - just as it would be to look for a FOR loop inside the rover. ("All I see is electrons!")

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