If you saw the movie "Contact", starring Jodie Foster, you might know "Occam's Razor" as: "the scientific principle that, all things being equal, the simplest answer is usually the right one."
And since Occam's Razor seems to be a recurring theme lately, let us explore it a bit. First, some background. William of Occam (or Ockham, or any number of alternate spellings) was a 14th-century English logician and Catholic friar on whose writings the phrase "entia non sunt multiplicanda praeter necessitatem" is based, or, for you and me: "entities should not be multiplied beyond necessity".
Are we lost yet? What Occam was trying to say was that, when trying to explain or prove something, we should refrain from making more assumptions than are necessary.
The fewer assumptions we make, the better. Occam's razor (or Ockham's razor), is the meta-theoretical principle that "entities must not be multiplied beyond necessity" (entia non sunt multiplicanda praeter necessitatem) and the conclusion thereof, that the simplest solution is usually the correct one.
Occams Razor is a process used to decide which interpretation is the most logical by taking the one that uses the least number of assumptions. In science, Occam's razor is used as a heuristic (rule of thumb) to guide scientists in the development of theoretical models rather than as an arbiter between published models. In physics, parsimony was an important heuristic in the formulation of special relativity by Albert Einstein, the development and application of the principle of least action by Pierre Louis Maupertuis and Leonhard Euler, and the development of quantum mechanics by Louis de Broglie, Richard Feynman, and Julian Schwinger.
In chemistry, Occam's razor is often an important heuristic when developing a model of a reaction mechanism. However, while it is useful as a heuristic in developing models of reaction mechanisms, it has been shown to fail as a criterion for selecting among published models. One argument against Occam's Razor is that science simply does not progress through logic, it progresses by demonstrations of which theories better fit and better explain the data. This alone is a much better guide to theory choice than Occam's Razor. This requires a literally understanding of the word "logic" versus "practical application." For more information on this topic see: Wikipedia and Occam's Razor.
Understanding Occam's Razor is an important part of the neuromarketing process used by Theme Zoom and Network Empire's IS-DNA questioning progress.