Oc·cam's ra·zor

(ŏk'imz rā'zŏrh),

The principle of scientific parsimony. William of Occam (ca. 1282-1340) stated it thus: "The assumptions introduced to explain a thing must not be multiplied beyond necessity."

Farlex Partner Medical Dictionary © Farlex 2012

The simplest expression of scientific truth; where 2 theories exist to explain a similar phenomenon, the one making the fewest assumptions should prevail—i.e., it should be no more complicated than necessary. In keeping with Occam’s razor, generalisations should be based on observed facts and not on other generalisations

Occam's razor

A principle in science and philosophy, much applied in medicine, that one should try to account for an observed phenomenon in the simplest possible way and should not look for multiply explanations of its different aspects. For instance, a range of symptoms and signs occurring together should always, if possible, be attributed to a single disease rather than to several different diseases occurring simultaneously. (William of Occam, ca. 1290–1349, English philosopher).

Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005

Occam's razor

see OCKHAM'S RAZOR.

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005

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References in periodicals archive

A useful starting point for thinking about the appropriate level of supervision is the principle of parsimony. Parsimony is the idea that penalties should be no more severe than necessary to serve the state's legitimate interests.

PRINCIPLES OF PRETRIAL RELEASE: REFORMING BAIL WITHOUT REPEATING ITS HARMS

145) describes the injunction not to postulate entities beyond those that have explanatory power as the principle of parsimony (my emphasis).

Quantitative parsimony

This is why, in the very section where Kant argues for an objectively valid (or perhaps merely regulative) "transcendental" principle of parsimony, he also devotes considerable energy to articulating the operation of a hypothetical or "logical" use of this principle.(37) Kant describes how, proceeding from the bottom up, this "logical" use groups specific types of event together in a genus and takes a generalized version of the specific causal rule holding for one of them to be a law holding analogously for all.

Kant's empiricism

We must rely on the principle of parsimony here to support the hypothesis that fog basking has evolved twice.

Adaptation and constraint in the evolution of the physiology and behavior of the Namib desert tenebrionid beetle genus Onymacris

Similarly, in the United States Norval Morris and Michael Tonry have advocated the principle of parsimony as the leading principle, asserting that desert is relevant only as providing upper limits on punishment and that utilitarian considerations may be mobilized to take individual sentences downwards.(16) They castigate the principle of equality before the law as a principle of "equality of suffering," and seem prepared to accept lower sentences whenever they can be justified in some way, irrespective of the different impact they may have on offenders.

Justifying the grounds of mitigation

Such a mapping is achieved through "character state optimization" and follows the general application of the principle of parsimony to phylogenetic reconstruction (Sober 1988; Carpenter 1989; Armbruster 1992).

Using phylogenies to test hypotheses of adaptation: a critique of some current proposals