From the middle of the Nineteenth Century, nearly every modern book on Logic has contained the words:Įntia non sunt multiplicanda, praeter necessitatem: However, it does not mention that the principleīecame associated with Ockham relatively late in history.Ĭuriously, only the eccentric internet encyclopedia Wikipedia gets the details correct, inġ. Marilyn McCord Adams, says that the principle is one that dictates a bias in towards simplicity in theoryĬonstruction (true) and says 'Although found in Aristotle, it became associated with William of Ockham because itĬaptures the spirit of his philosophical conclusions' (also true). Oxford Companion to Philosophy (1995 edition) says, in an article on the Razor written by Known philosophical contributions is the philosophical principle of 'Ockham's Razor', a rule of ontologicalĮconomy to the effect that 'entities are not to be multiplied beyond necessity'.

Chambers Biographical Dictionary (2000 reprint) says that one of William's best The Penguin Encyclopedia (2004 edition) says that William deployed the rule of ontologicalĮconomy 'entities are not to be multiplied beyond necessity' so frequently and to such effect that it became For example, Collins English Dictionary reprint of 1989, says the maxim is 'attributed to William of Ockham',

Most modern reference works either perpetuate the myth, or fail to mention it. I will attempt translations at some point to help modern readers. Thorburn, in common with educated chaps of his time,ĭid not bother translating these quotations. That used elsewhere in The Logic Museum, which is intended to facilate Google searches. I have not altered the Latin quoted by Thorburn, except to imposed a Latin spelling consistent with This discovery ought to operate as a salutary check upon dogmatism, and the tendency to turn logical rules into ontological principles.' The value of this warning has just now received signal illustration from the very recent discovery of Chemical Isotopes, which has proved (e.g.), that what had previously been simply called 'lead' is infinitely complex in its compositions. Or than we have any actual reason to suppose. 'We know too little of the ultimate constitution of the Universe, to assume that it cannot be far more complex than it seems, The appendix at the end has useful locates all the places where Ockham uses the medieval formula Frustra fit &c.Īnd there is a curious observation at the end, where he says To find phrases like 'Entia non temere (sine necessitate) multiplicanda'. (for example Clauberg's Elementa Philosophiae seu Ontosophia (Groningen, 1647), Thorburn also trawled through early modern works (mostly in Latin) that are incredibly obscure The entire works of Aquinas are now on the web ( here), Certainly, Google so far bears his claim out. (I am not so sure what he means by this). The Sentences of Peter Lombard (Bishop of Paris, +1164), and the Summulae Logicales of Petrus Hispanus.Īnd he adds with sufficient moral certainty, Abelard, Hales, Albert, Bonaventura, and Durand. He adds that the axiom does not occur in the two most popular textbooks of the Middle Ages, That the scholastics who used the expression non sunt multiplicanda entia sine necessitateĭo not include Ockham, Scotus, or Aquinas - I take him to mean that he has read through the entire output

Thorburn claims that he can says with almost mathematical certainty The label 'Ockham's Razor' was first applied in 1852 by Sir William Hamilton. The maxim 'Entia non sunt &c' was first associated with Nominalism by Leibniz in 1670.ĥ. However, these maxims, though employed by Ockham, did not originate with him. ( Pluralitas non est ponenda sine necessitate).ģ. It does capture the spirit of genuinely medieval maxims of the form 'plurality is not to be supposed without necessity ( Entia non sunt multiplicanda praeter necessitatem is not medieval at all,īut was invented in 1639, substantially in its present wording, by the Scotist Commentator, John Ponce of Cork.Ģ. That the maxim 'Entities should not be multiplied without necessity' The principle that entities should not be multiplied beyond necessity, is a 'modern myth'. William Thorburn gives convincing evidence that what is now called 'Ockham's Razor', Here is a paper that deserves to be better known.

William of ockham quote