Monday, July 03, 2006

Free Will and Determinism

Why do so many people who claim humans have free will dismiss the deterministic-random dichotomy, and regard free will as a third option?

We recognize that a system is deterministic when we recognize the laws that determine its future state. We recognize that a system is random when we fail to recognize any laws that determine its state. So, what does it mean to recognize that a system is free?

We are familiar with the idea that a man can make a decision of his own free will. A decision made by free will is not made under duress or under "abnormal" external influence (e.g., the decision was not induced by mind-altering drugs). Using this same definition, we can see that it really doesn't matter whether the decision-making process was fully or partially deterministic. What matters is whether the decision was significantly determined by a certain class of external influences.

Thus, there is really no direct connection between "free will" on the one hand, and determinism-randomness on the other.

Where, then, does the mistaken link between free will and determinism come from? The problem arises when we disproportionately focus our attentions on the determinism required for coercion, and ignore the determinism required for free decision-making. For an external influence to coerce a decision, there has to be some causal link between the influence and the decider. However, for the decider to be able to make a free decision that weighs options against the decider's values, there must also be some determinism. Otherwise, a person could not be trusted to make any given decision freely with any reliability at all. In that case, we would not even need a word for "decision."

One clue that the link between free will and determinism is a false one comes from a linguistic analysis of the statement "humans make free decisions, i.e., decisions that are neither deterministic nor random, nor a simple combination of the two."

How would we recognize the difference between humans making free decisions and humans making non-free decisions? After all, if we are going to name a decision as free, we had better be able to recognize free ones versus non-free ones. Our inability to do this is a clear signal that we have stretched our definitions beyond recognizable limits.


Ken Brown said...

I think you are the one confusing definitions. Normally, when free will and determinism are distinguished, the point is that a free system is contingent –- it could result in more than one outcome, given the starting conditions -- while a deterministic system is not contingent –- it can only result in one outcome. But you want to replace contingency with randomness, and further, to equate randomness with “uncaused.” This cannot work.

You say, “a system is random when we fail to recognize any laws that determine its state” and distinguish “caused (deterministically constrained) or uncaused (random and unconstrained)” events. To be sure, if an event were to occur for which nothing was the cause, we would rightly call it “random,” but that would seem to be an empty class of events. Usually when we say “random” we mean “uncorrelated.” Thus when biologists say genetic mutation is “random,” they mean “not correlated with evolutionary fitness.” They are saying that mutations are not predetermined to be beneficial, not that they are uncaused. Indeed, in the real world the very concept of randomness seems to depend on a perceived standard (in this case, survivability), not on the lack of a cause.

You can say an event is random with respect to a particular standard, or even random with respect to all known standards (or laws), but you can’t say it is simply “random.” Randomness depends on contingency, but it does not equate with it, and it certainly does not mean “uncaused.” A contingent system can result in more than one outcome, but which outcome does result will still be caused by something, the only question is whether that cause correlates with a meaningful standard or not (and whether the outcome could have been different).

This means there are three options: either a system is truly deterministic (capable of resulting in only one outcome) or it is contingent (capable of resulting in more than one outcome). But if it is contingent, then the outcome that results could be either random (uncorrelated to any known standard or law) or specified (correlated to a known standard).

An event that is specified could result from either a contingent or a deterministic system, so after the fact there might be no empirical difference between the two. However, before the fact there seems to be a very clear conceptual difference between determinism, specification and randomness.

The ability to impose a specification onto a contingent system, or not, is part of what we call “free will.”

Doctor Logic said...


Are you saying that a free action is one that is not fully determined by some limited subset of causes?

For example, my decision to buy an Acura Integra was not fully determined by the constraint that I buy a car that I could afford. That is, this single constraint was insufficient to determine which car I purchased. My choice was contingent, given only the constraint that my car be affordable. I was free to choose any car below a certain price.

Of course, this says nothing about whether my purchase choice could, in principle, have been predicted two weeks before by accounting for all possible variables, e.g., what I had for lunch each day, my past experiences, which salespeople happened to be working in the dealership that day, etc.

Is this what you mean by free?

If so, what we call "free" would still have little to do with determinism per se. It has to do with whether, arbitrarily accounting for only a subset of metaphysically possible causes, the outcome was determined. Even if the universe were totally deterministic, I would still have been "free" to choose the Acura if price were the only arbiter of free choice.