William of Ockham

Ockham was a Franciscan friar, a fierce critic of papal corruption, and the great late-medieval nominalist — meaning he denied that universal terms ("redness," "humanity") refer to real things in the world. Only individuals exist. Universals are names (nomina), useful labels we attach to bundles of similar particulars.

His name now stands for Ockham's razor: when explaining anything, prefer the explanation with the fewest entities. The principle predates him, but he wielded it with such force that it became his. Stripped of Platonic Forms and unnecessary metaphysical machinery, the world becomes flat, particular, modern.

The razor is the patron saint of modern science. Anything that looks like Occam-style parsimony — minimum description length, Bayesian priors, "all things equal, prefer the simpler hypothesis" — is his descendant.