Saturday, July 18, 2009

Some Thoughts On Ockam's Razor and Induction

A blogger name John Pieret has also criticized Sean Carroll's article about naturalism, though I think his criticisms are somewhat misguided. I just left the following comment on his blog:

I have major problems with Carroll's treatment of naturalism and supernaturalism. (See here: Discovery, Demonstration, and Naturalism.) However, I don't agree with all of your points; specifically about Ockam's Razor and the so-called "problem of induction."

Ockam's Razor is an indispensable explanatory tool. Consider the situation with ID again.

IDers might claim that ID is simpler than natural evolution, that Ockam's Razor weighs in their favor. The question is, are they right?

The answer is: of course not. Natural evolution does not postulate any entities beyond our explanatory framework, and it does not postulate anything superfluous. It does not postulate entities beyond necessity.

ID, on the other hand, postulates an "intelligent designer" which is outside of our explanatory framework, which is not (and, some IDers would say, cannot be) explained. ID does not explain how the "designer" has done anything. It does not explain anything.

Ockam's Razor is not the principle of least effort. If it were, then any predictive theory would lose against hand-waving. No, the razor does not favor the argument which requires the least amount of work. Rather, it says, the best explanation is the one that does not postulate unnecessary entities. (Necessity is recognizable by comparing two competing theories.) Clearly the razor favors natural evolution, and nothing "supernatural."

Okasha's argument [that Ockam's Razor suggests that nature is simpler than it might really be] is not convincing, because the razor does not require us to claim that nature is "not complex." Rather, it requires us to recognize the uselessness of postulating unnecessary entities. Our theories should be as complex as necessary to make good predictions, and no more. This does not require making any assumptions about how simple or complex nature really is.

As far as the problem of induction and the Alpha Centauri example: I think Carroll did misrepresent the scientific view there. It is not that scientists claim outright, "of course momentum was conserved!" Rather, they predict that momentum is conserved, and maintain that attitude unless given strong enough reason to change it.

There is no problem of induction in science, however, because predictions are not induced by finite sets of examples. Rather, they are deduced from theoretical frameworks which define examples as such.