New Occam’s Razor

This post follows others written about Occam’s razor here and here and here. The flaw of Occam’s razor has been identified: the parsimony it privileges is biased against qualitative explanations and in favor of quantitative explanations.

Here’s a simple example: “the hypothesis that the damage to my lawn was caused by 12 rabbits is less quantitatively parsimonious but more qualitatively parsimonious than the hypothesis that it was caused by 1 deer and 3 rabbits.” Simplicity, Stanford Encyclopedia of Philosophy.

William of Ockham adopted the idea now usually stated as, “Entities must not be multiplied beyond necessity.” This is understood to mean that qualities must not be multiplied beyond necessity, whereas quantities may be. The introduction of new qualities should be avoided or minimized but known qualities may be multiplied indefinitely.

So atomic theories have been preferred to elemental (natural kind) theories. The periodic table of the elements shows the happy confluence of atomic and elemental theories, but that is an exception. More common is how qualitative but not quantitative parsimony enables one explanatory resource to be multiplied a vast amount.

Time in particular has been multiplied since there’s no penalty for vastly expanding time. This encourages for example biology to focus on the possibility that there is only one natural kind of organisms. If other resources are multiplied (e.g., fortuity, self-organization, money, etc.), other theories would result so that the type of parsimony determines the types of theories enabled.

The New Occam’s Razor is simply, “Explanatory resources must not be multiplied beyond necessity.” That puts all explanatory resources on an equal footing. In particular, quality and quantity are treated the same. There is no fixed rule that says X new qualities equals Y new quantities but the pressure is on to minimize both.

In the simple example above, if the damage to one’s lawn can be explained with 1 deer and 2 rabbits, that should be preferred. Or if there is evidence that many rabbits but few deer are in the vicinity, then 12 rabbits should be preferred.

The quantity of matter, antimatter, dark matter, space, time, etc. should all be minimized as much as any other explanatory resource. New qualities should be minimized as they have been, but now in concert with minimizing new quantities and other explanatory resources.