The simplest definition of Occam's Razor is "Don't make unnecessarily complicated assumptions". It can be used as a philosophical way of sorting the simple theories from the complicated ones (Cohen & Stewart, 1994). When scientists select theories, they don't just use the criterion of agreement or disagreement with observations. They also have aesthetic principles, and a desire for an elegant, universal theory. They use these aesthetic principles to remove the cloud of trivially competing theories that necessarily surround every theory. Occam's razor is a working rule of thumb, not the ultimate answer. It is named after the 14th century English Friar William of Ockham. It is also known as the law of parsimony
- Cohen J., & Stewart, I. (1994). The collapse of chaos. New York: Viking Press.
(Revised November 2010)