Occam's Razor

Paraphrased as:

"The simplest explanation for a phenomenon should be preferred, all else being equal."

Overview

Occam's razor is a principle of parsimony that suggests the simplest explanation for a phenomenon should be preferred, all else being equal. It advises against making unnecessary assumptions or positing extra entities when a more straightforward explanation will do.

Although often attributed to the fourteenth-century English Franciscan friar and philosopher William of Ockham (c. 1287–1347), the idea predates him. Ockham did not coin a single definitive phrase, but he expressed the principle in various forms in his Latin writings.

Original form (Latin)

"Frustra fit per plura quod potest fieri per pauciora."
"It is pointless to do with more what can be done with fewer."

A later formulation summarising his thought:

"Entia non sunt multiplicanda praeter necessitatem."
"Entities should not be multiplied beyond necessity."

Notes

• Occam's razor does not claim that the simplest explanation is always correct, but rather that it should be the default starting point. If a more complex explanation becomes necessary and is supported by evidence, the principle allows for it.
• In science, philosophy, and problem-solving, Occam's razor serves as a heuristic: a guiding rule of thumb encouraging simplicity in theory and model building, unless complexity is warranted by data.
• Einstein's Razor supplies the other half of the condition: as simple as possible, but not simpler. Occam's Broom is what happens when simplicity is achieved by hiding the data instead.

Also see

• William of Ockham
• Occam's Broom
• Einstein's Razor
• Popper's Razor
• Hitchens' Razor
• Alder's Razor
• God, where the razor is applied to the supernatural

Wikipedia: https://en.wikipedia.org/wiki/Occam%27s_razor