Naturalism and First Philosophy: Logic & Rationality

I pointed out in an earlier post that the naturalist can still deny the necessity of first philosophy by claiming that the principle of non-contradiction is a component of something else (such as rational thought). This something else would then be justified on the basis of pragmatic value or experience. This is the final move available to the naturalist. This forces the naturalist to ground rationality by design, accident or necessity.

The idea that the principle of non-contradiction is a component of rational thought is surely true. In fact, to the extent that one denies the principle in practice one is no longer thinking rationally. So the principle of non-contradiction is a necessary condition of rationality - both practically and theoretically. However, one would not want to claim that the principle is a sufficient condition. The belief that the President is an alien because the voices told me is irrational. Yet is not contradictory.

Once again one can note that rationality can be justified pragmatically in one of two ways. Either one can claim that one's experience grounds one's belief in one's rationality or that one's rationality is grounded in the circumstances of its origin. Since rationality is a practice, it cannot be grounded unless it works correctly. I am assuming that one is rational if and only if one's thinking processes that are aimed at the truth function in a way consistent with their aim, and that at least some of one's thinking processes do aim at the truth. Now our rationality can be grounded in historical circumstances only if these circumstances caused our rationality to be truth aimed. One's experience cannot ground rationality itself, it can only justify beliefs in one's own rationality. Since that is a different claim, I will focus on the actual ground of rationality rather than our belief that we are rational.

To point out the grounding problem in a different way, consider it as the question of why it is that our thinking processes that are aimed at the truth function in a consistent manner, and why we have such processes. These are two different ways of looking at the same problem. Since the naturalist believes that science (or empirical investigation) must provide the answer to this question. Therefore, if naturalism is true then empirical investigation will be able to discover both why we have thinking processes that are aimed at the truth and why these processes are consistent. Since empirical investigation is done using rational methods, the results obtained are meaningful only if they were obtained by a rational method. That means that empirical investigation cannot ground rationality. It can only tell us (at most) what occurred in order to give us the rational processes we do have.

Since no empirical investigation has been done on the matter, one must proceed hypothetically. There are several different ways that rationality could be grounded. It could be grounded as the aim of a particular process. In that case, rationality would be designed as such. It could be grounded as the product of particular process in which rationality was an accidental by-product. This would be the case in which rationality was not designed but was made. It could also be grounded in necessity. This is the case in which rationality is eternal and so are our processes. These separate options must each be addressed before naturalism gives way to first philosophy.