Ockham’s razor

The simplest or most obvious explanation of several competing ones is the one that should be preferred

Ockham’s razor is the idea that, in trying to understand something, getting unnecessary information out of the way is the fastest way to the truth or to the best solution.

William of Ockham (1285-1349), English theologian and philosopher,
Ockham was noted for his insistence on paying close attention to language as a tool for thinking and on observation as a tool for testing reality. His thinking and writing is considered to have laid the groundwork for modern scientific inquiry.

Ockham’s insistence on the use of parsimony (we might call it minimalism) in thought resulted in some later writer’s invention of the term, Ockham’s razor.

Among his statements (translated from his Latin) are: “ Plurality is not to be assumed without necessity ” and “ What can be done with fewer [assumptions] is done in vain with more.”

One consequence of this methodology is the idea that the simplest or most obvious explanation of several competing ones is the one that should be preferred until it is proven wrong.

From http://whatis.techtarget.com/definition/0,,sid9_gci212684,00.html