Friday, 12 December 2008

Occam's Razor

Occam's Razor:

"One should not increase, beyond what is necessary, the number of entities required to explain anything."

This is one of the various translations for Occam's famous saying. The more familiar phrasing that one usually sees is that the simplest explanation is usually the best explanation. What it means is that one should eliminate as many assumptions as possible in order to reach the best explanation. If two competing hypotheses are trying to explain the same phenomenon, and both work equally well, the one that has the least assumptions behind it would be preferred. Also, the one that adds the least amount of entities would be preferred, and adding complexity to the problem is not preferred.

It's ironic, then, that Occam was a friar, because his very simple argument is not at all beneficial to theism. Some theists claim that Occam's Razor is supportive of their faith, that evolution and science are complex and that positing a god is the more simple route, and therefore preferred. This is a gross misunderstanding of the idea, however, in that positing a new layer that is more complex than any other is not the preferred explanation for anything, and god is the most complex, unnecessary layer that one can add. (Note, I've also seen theists claim that goddidit seems like the simplest explanation to them, so therefore they use Occam's Razor to affirm their belief, but this falls into the same problem as above, and also adds an extra layer of subjective assumptions and hence is an even worse formulation.)

1 comment:

Maria Salva said...

In addition to adding an entirely new layer of complexity, theistic explanations for the origin and development of life don't really work under Ockham's razor, since they'd naturally involve neglect for the empirical evidence. Ockham's razor favors the simplest possible explanations, with respect to the amount of available evidence. Back in the time of the ancient Greeks, the simplest possible explanation for matter might have been a view of atoms as solid spheres, with four elements, and a fifth kind of atom responsible for a soul. But once we find that gold foil can repel a few alpha particles, for example, that view just doesn't fit in with the evidence, and the simplest possible view is one of an atom that consists mostly of empty space, but with a dense, positive nucleus. The same thing could be said about the soul idea held by those same early atomists. It isn't that the world is necessarily as simple as possible--it might be full of complexities that we're unaware of. But if we start adding complexities arbitrarily, we're not likely to land on the particular correct complexities that actually exist. The simplest possible explanation is the one that is most likely to be closest to the reality of the situation. But once there's the evidence to suggest complexity, you really can't avoid it by pleading Ockham.