Naturalism and First Philosophy: Logic As Practice

The last post pointed out that naturalism (of the epistemic variety) assumes that first philosophy is unnecessary. I used the example of the principle of non-contradiction as a counter-example to this claim. I pointed out that naturalists have at least three responses to this claim, and refuted the first response. At this point the naturalist could claim that the principle of non-contradiction is not a belief. If this response is successful, then the naturalist has successfully defended her theory from my attack.

The naturalist might believe that the principle of non-contradiction is a proposition describing the behavior of human being when believing. No one believes contradictions. She could extend this even farther. Quine describes his two principles as pragmatic principles, not beliefs or rationally based principles. If the principle is not a belief, then she could explain adherence to it in pragmatic terms. We behave in this way because believing contradictory things decreases survival value. Since it is not a belief, there is no need to provide a justification for it.

The question to ask is this: do people ever believe that the principle of non-contradiction is true? If anyone does, then the question of justification enters again, and naturalism is defeated. So someone who believes that principle is not a belief must also believe that the principle is neither true nor false. Anyone who claims to believe the principle is either mistaken (because they actually do not believe it) or ignorant.

There are implications for that kind of belief. First, not all instances of P & not-P can be false. If they were, then the principle of non-contradiction would be true. So there is a severe problem. It gets worse, for there is no rational reason to object to any instance of P & not-P. If I claim that the moon is both white and not-white, how could you object apart from claiming the truth of the principle of non-contradiction? All of this demonstrates that if we are to accept the idea that the principle of non-contradiction is neither true nor false, then all of our rational thinking would vanish. Therefore, the principle of non-contradiction must be true. Since the principle is either true or false, one can believe it. Therefore, the second strategy against accepting an example of first philosophy has been refuted.

There is a final strategy available to the naturalist. She could claim that the principle of non-contradiction is a component of something (such as rational thought) that has pragmatic value, or that is not a belief, or is in some way is justified by experience. That possibility is for later.