Ockham's Razor

Ockham's Razor — also called the principle of parsimony — is the methodological rule that entities should not be multiplied without necessity. In metaphysics, it functions as a selection criterion between competing theories: all else being equal, the theory with the sparser ontology is preferable. The principle is named after the medieval philosopher William of Ockham, though its lineage extends to Aristotle. In contemporary philosophy, Ockham's Razor is the engine behind nominalism and ontological naturalism, but critics note that parsimony is a virtue only when the simpler theory retains equivalent explanatory power — a condition that abstract-object theorists frequently dispute.