Principle (attributed to William of Ockham) that in explaining a thing no more assumptions should be made than are necessary
Introduction to the notion
Okham’s razor refers to the principle that, when faced with competing hypotheses that are equal in other respects, the one that makes the fewest new assumptions should be selected. The principle has been attributed to Father William of Ockham, a 14th century English logician, theologian and Franciscan friar, although the principle existed prior to his use of it.
It is also expressed in Latin as the lex parsimoniae (the principle or law of parsimony)
Ockham’s razor is also phrased as:
- entia non sunt multiplicanda praeter necessitatem (“entities must not be multiplied beyond necessity”)
- pluralitas non est ponenda sine necessitate (“plurality should not be posited without necessity”)
New expressions of Ockham’s razor have arisen over the centuries. Isaac Newton made one such re-interpretation:
“We are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances. Therefore, to the same natural effects we must, so far as possible, assign the same causes.”
Source: Oxford Dictionary
Related terms: Occam’s razor, the law of parsimony.