What is Ockham's Razor?

Ockham's razor (or Occam's razor, Achem's razor) is the argument that in order to understand something, we shouldn't invent elaborate explanations that use useless information. The Galilean library gives the crop circles phenomenon as an example, explaining that a popular belief is that crop circles are caused by aliens, usually with their aircraft, while others believe that they are the work of guerilla artists or those making the circles an elaborate hoax. Ockham's razor would argue that since it can't be proved that aliens cause the crop circles, they shouldn't be used as a part of the explanation for them. As the Galilean library states, "we should pick the simpler explanation", especially since people have been able to reconstruct the crop circles. (1)

A page on University of California, Riverside's website by Jose Wudka explains that while Ockham's razor can be simplified as "keep it simple", it is a more complex and effective argument. The page states that if there are two possible explanations for something, experimenting should prove which explanation is better, and if they both reach the same conclusion, opt for the one that doesn't have "additional baggage". (2) If you left a plate of cookies on the living room table, then return to find most of them gone, you could obviously conclude that someone ate them, but if you conclude that it was either the work of your roommate or leprechauns, you're better off asking your roommate if he helped himself to the treats. Unless you see leprechauns wandering around your home, there's no reason to think the Irish creatures helped themselves to the cookies.

The Skeptic Dictionary gives the background of Ockham's razor, which originated with William of Ockham, an English philosopher and medieval Franciscan monk. As the dictionary describes, monks favor minimalism, "idealizing a life of poverty", which is the basis for Ockham's razor, "Pluralitas non est ponenda sine neccesitate" ("plurality should not be posited without necessity"). (3) The unusual name for the argument might explained by Principia Cybernetica Web's article, which states that Ockham's Razor helps to "shave off" useless concepts. (4)

Ockham's Razor is popular in debates, and is often used in the arguments for and against religion, namely the existence of God. Both atheists and creationists have used Ockham's Razor in arguing against the existence of God and the theory of evolution, respectively. The Skeptic Dictionary argues that the creationist use of Ockham's Razor is incorrectly used, since while it's simpler to believe that God created man and man is not evolved from primitive apes, it "does not say that the more simple a hypothesis, the better" and "Occam was concerned with fewer assumptions", not just the easier argument. The dictionary also suggests it could be called "Ockham's Chainsaw" as its effective use as an argument against the existence of God. (3)

Ockham's Razor is a useful tool in finding explanations for missing cookies and different species, as the Stanford Encyclopedia of Philosophy cites Buffon's Law ("Areas separated by natural barriers have distinct species") as an example of Ockham's Razor's effectiveness. (5) A more complex version of "keep it simple", Ockham's Razor supports arguments that don't feature leprechauns, aliens, and in some instances, even God.

SOURCES:

1 - "Ockham's Razor" By Paul Newall. The Galilean library, 2005. (http://www.galilean-library.org/or.html)

2 - "What is Ockham's Razor?" By Jose Wudka. University of California, Riverside, Department of Physics and Astronomy, September 24, 1998.
(http://physics.ucr.edu/~wudka/Physics7/Notes_www/node10.html)

3 - "Occam's razor" By Robert Todd Carroll. The Skeptic Dictionary, 2006 (http://skepdic.com/occam.html)

4 - "Occam's Razor" By F. Heylighen. Principia Cybernetica Web, July 7, 1997. (http://pespmc1.vub.ac.be/OCCAMRAZ.html)

5 - "Simplicity (Stanford Encyclopedia of Philosophy)" by Alan Baker. October 29, 2004. (http://plato.stanford.edu/entries/simplicity/)