C.S. Peirce

There never was a sounder logical maxim of scientific procedure than Ockham’s razor: Entia non sunt multiplicanda praeter necessitatem. That is to say; before you try a complicated hypothesis, you should make quite sure that no simplification of it will explain the facts equally well.

Charles Sanders Peirce, Lectures on Pragmatism delivered in Cambridge, Massachusetts (March 26 — May 17, 1903).