# What is the proper characterization of Occam's Razor? **URL:** \ **Category:** Factual Questions\ **Created:** [August 7, 2005, 4:12am UTC](https://boards.straightdope.com/t/what-is-the-proper-characterization-of-occams-razor/315957 "2005-08-07T04:12:09Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Measure\_for\_Measure](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/measure_for_measure/32/557_2.png) [@Measure\_for\_Measure](https://boards.straightdope.com/u/Measure_for_Measure)\ **Post date:** [August 7, 2005, 4:12am UTC](https://boards.straightdope.com/t/what-is-the-proper-characterization-of-occams-razor/315957/1 "2005-08-07T04:12:09Z")
Some say Occam’s Razor (OR) is about simplicity, others say necessity, still others maintain that it is about eschewing unnecessary steps in an argument. Where can I find a good treatment of OR? A tangent in this thread provides some assertions: [http://boards.straightdope.com/sdmb/showthread.php?t=328800](http://boards.straightdope.com/sdmb/showthread.php?t=328800) Wiki article, criticized by a poster: [http://en.wikipedia.org/wiki/Occam’s\_Razor](http://en.wikipedia.org/wiki/Occam's_Razor) I haven’t yet investigated this topic at the various internet encyclopedias of philosophy. I hope to do so, but I suspect that the conversation here might be fruitful regardless. ---
**Author:** ![Zeldar](https://avatars.discourse-cdn.com/v4/letter/z/b77776/32.png) [@Zeldar](https://boards.straightdope.com/u/Zeldar)\ **Post date:** [August 7, 2005, 4:38am UTC](https://boards.straightdope.com/t/what-is-the-proper-characterization-of-occams-razor/315957/2 "2005-08-07T04:38:10Z")
> [@Measure for Measure](#): > > Some say Occam’s Razor (OR) is about simplicity, others say necessity, still others maintain that it is about eschewing unnecessary steps in an argument. > > Where can I find a good treatment of OR? > > A tangent in this thread provides some assertions: [http://boards.straightdope.com/sdmb/showthread.php?t=328800](http://boards.straightdope.com/sdmb/showthread.php?t=328800) > > Wiki article, criticized by a poster: > [http://en.wikipedia.org/wiki/Occam’s\_Razor](http://en.wikipedia.org/wiki/Occam's_Razor) > > I haven’t yet investigated this topic at the various internet encyclopedias of philosophy. I hope to do so, but I suspect that the conversation here might be fruitful regardless. If you’ll permit a personal assessment, not necessarily supported by a cite or reference, but from forming my own opinion from various contexts where I’ve encountered its use, I would say that it’s a way of saying: If you have a choice between two explanations for something, go with the one with fewer interdependent variables. Go for simple not complex. ---
**Author:** ![Liberal](https://avatars.discourse-cdn.com/v4/letter/l/848f3c/32.png) [@Liberal](https://boards.straightdope.com/u/Liberal)\ **Post date:** [August 7, 2005, 9:05am UTC](https://boards.straightdope.com/t/what-is-the-proper-characterization-of-occams-razor/315957/3 "2005-08-07T09:05:43Z")
William of Ockham stated his razor two ways: (1) Frustra fit per plura, quod potest fieri per pauciora. (It is pointless to do with more what can be done with fewer), and (2) Pluralitas non est ponenda sine neccesitate (Entities should not be multiplied without necessity). [This site](http://math.ucr.edu/home/baez/physics/General/occam.html) explains why it is a mistake to equate Ockham’s Razor with the Law of Parsimony, or Rule of Simplicity. ---
**Author:** ![PatriotX](https://avatars.discourse-cdn.com/v4/letter/p/c4cdca/32.png) [@PatriotX](https://boards.straightdope.com/u/PatriotX)\ **Post date:** [August 7, 2005, 2:31pm UTC](https://boards.straightdope.com/t/what-is-the-proper-characterization-of-occams-razor/315957/4 "2005-08-07T14:31:14Z")
I’ve always thought it was merely a guideline to be used when deciding which theory to test first. The theory with the fewest variables would be the easiest one to eliminate as incorrect. ---
**Author:** ![SiXSwordS](https://avatars.discourse-cdn.com/v4/letter/s/49beb7/32.png) [@SiXSwordS](https://boards.straightdope.com/u/SiXSwordS)\ **Post date:** [August 7, 2005, 7:49pm UTC](https://boards.straightdope.com/t/what-is-the-proper-characterization-of-occams-razor/315957/5 "2005-08-07T19:49:35Z")
What the WIKI article says is: > [@](#): > > _ **Put into everyday language** _, [occam’s razor] says > > The simplest explanation is the best. emphasis mine Ironically, by trying to simplify the issue, one creates a logical error. Bertrand Russell expressed occam’s razor as something like: Whenever possible, substitute contructs from known entities for inferences to unknown entities. (not exact words, but close) It interests me that both William of Ockham and Bertrand Russell spent a fair amount of energy undermining grandiosity. Russell, for example, disliked Plato’s concept of _The Forms_. Russell came up with a formula that he believed clarified many apparent paradoxes that had led philosophers to posit other worldly solutions. > [@](#): > > There is an entity C, such that the sentence ‘X is Y’ is true if and only if X = C. It’s a little unwieldy, but he thought it helped prevent _inferences to unknown entities_. ---
**Author:** ![Measure\_for\_Measure](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/measure_for_measure/32/557_2.png) [@Measure\_for\_Measure](https://boards.straightdope.com/u/Measure_for_Measure)\ **Post date:** [August 7, 2005, 7:53pm UTC](https://boards.straightdope.com/t/what-is-the-proper-characterization-of-occams-razor/315957/6 "2005-08-07T19:53:51Z")
Thanks for the cite **Lib**. Permit me to summarize. Occam’s razor (actually a 19th century term) applies to competing theories with identical predictions. It advises the thinker to choose the version with the smallest number of elements. The Law of Parsimony takes this a step further. In the formulation attributed to Einstein it states, “Everything should be made as simple as possible, but not simpler.” That is, choose the simplest theory _that is adequate to explain what facts are known_. Note that the Law of Parsimony can apply to theories that make different predictions. Strictly speaking then, it should not be used to make or defend a final conclusion: “As arbiters of correctness only logical consistency and empirical evidence are absolute.” (from **Lib** ’s link). At the same time, Occam’s Razor is necessary for science to exist at all, since there are an infinite number of (mostly redundant) explanations that can explain a finite set of facts. See [the section “In Science”](http://www.answers.com/topic/occam-s-razor) in the Wiki article on Occam’s Razor. ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [August 8, 2005, 1:19am UTC](https://boards.straightdope.com/t/what-is-the-proper-characterization-of-occams-razor/315957/7 "2005-08-08T01:19:12Z")
> [@PatriotX](#): > > I’ve always thought it was merely a guideline to be used when deciding which theory to test first. > The theory with the fewest variables would be the easiest one to eliminate as incorrect. Yes. Occam’s Razor should never be used to validate a theory based on its simplicity; only that a simple theory is easiest to eliminate if it isn’t, in fact, valid. Actually, there are many arguments in which the simplest theory is \*\*not \*\*the most valid, e.g. intelligent design.