Occam

Occam, most often encountered in reference to William of Ockham, is a term associated with medieval philosophy and a widely used methodological guideline. William of Ockham (c. 1287–1347) was an English Franciscan friar, theologian, and scholastic philosopher noted for his work in logic and nominalism. The name Occam’s razor is linked to him through the tradition of favoring simplicity in explanation, though the exact wording of the principle does not appear in his surviving writings. The general idea is commonly summarized as choosing the explanation that makes the fewest assumptions, all else being equal.

Occam’s razor, or the principle of parsimony, is a heuristic rather than an inviolable rule. It encourages scientists and philosophers to favor hypotheses that account for data with minimal ontological commitments, avoiding unnecessary entities. Over the centuries it has informed reasoning in science, theology, and analytic philosophy, and it is routinely invoked in model selection, theory evaluation, and the construction of explanations.

In contemporary use, the razor helps compare competing theories by weighing their explanatory power against their complexity. However, simplicity alone does not guarantee truth, and there are cases where more complex theories better fit the evidence. The principle is often stated in various formulations, including the Latin phrase entiа non sunt multiplicanda praeter necessitatem, typically rendered as “entities should not be multiplied beyond necessity.”