Friday, July 23, 2010

A conclusive disproof of a conclusive disproof of free will

The New York Times philosophy column recently ran an interesting piece about free will. The thesis was that, whether or not one assumes a deterministic universe, one cannot be responsible for one's actions. What caught my attention here wasn't the thrust of the argument - it's simple enough - but the fact that it was presented, not as an opinion or a way of viewing life, but as a logical inevitability. This set my fallacy radar off something fierce, especially since the conclusion was one I disagreed with. So, if you're interested in things like proving we do or don't have free will, follow me for a bit as I take a look at the argument.

The argument, which the author refers to as Basic for some reason, goes as follows (direct quote):

(1) You do what you do — in the circumstances in which you find yourself—because of the way you then are.

(2) So if you’re going to be ultimately responsible for what you do, you’re going to have to be ultimately responsible for the way you are — at least in certain mental respects.

(3) But you can’t be ultimately responsible for the way you are in any respect at all.

(4) So you can’t be ultimately responsible for what you do.

(3) seems like the most obviously objectionable point here, and indeed, the author immediately informs us that "the key move is (3)." He then goes on to restate the argument inductively, justifying (3) as an assumption. You don't start out responsible for what you are (we can't help the way we're born), and the rest of the argument seems to show that we're not responsible for what we do when we're not responsible for what we are. But what we do determines what we become, so we can never be responsible for what we are, and the argument holds.

Not bad, not bad. One can always nitpick, but I think the logic's pretty sound here. But, as I'm sure is obvious by now, I'm not convinced. After all, as any logician knows, sound logic can easily get you to false conclusions: all you need to do is start with incorrect assumptions. And in this case, that focus on the oh-so-shocking point (3) obscured a more basic problem: point (1).

What's wrong with point (1)? Well, the author restates it a bit more rigorously later in the argument: "When one acts for a reason, what one does is a function of how one is, mentally speaking." A function? Really? The mathematical definition of a function, and the one being used by this author, is as an operator that takes in some inputs, and based on them produces precisely one output, completely determined by the inputs. In other words - wait a second - point (1) means that our actions are completely determined by our current state. That's nothing less than determinism! The argument was supposed to hold "whether determinism is true or false". But actually, the very first statement in it assumes determinism!

So much for that, then. If you believe that the universe is deterministic, then this is a pretty compelling argument against moral responsibility. There are a lot of those, though, if your basic assumption is that we have no control over our actions. If you don't take determinism on faith, this whole structure has probably proved nothing you didn't already know. It's refreshing to see a bit of rigor being brought into philosophical arguments presented for popular consumption; I wouldn't mind seeing more of this kind of article in the Times, if only because I so enjoy picking them apart. But I hope that people won't be too easily taken in by so-called conclusive arguments (mine included) without a careful examination of the premises.

Okay, then, hope you had fun!

1 comment:

  1. :D

    The issue I think is that the author is trying to evoke a fairly intuitive notion that "the way you are" is out of your control, and that if you're a smart person you'll act in a smart manner, and if you're a moral person you'll act in a moral manner, and then fails to specify the difference between this intuitive notion of "the way you are" and the fairly well defined concept of determinism.

    But then, my own perspective is that we have responsibility for our actions whether or not we have free will, so arguments for or against the existence of free will are mostly just entertaining to me.