I am getting a little bit lost when people in other threads refer to Occams Razor. The guys in the JFK thread use it all the time.
Can someone please let me know what it is and possibly give a quick example?
Thanks
The most likely reason for an event is generally the correct one.
Example: I left my car sitting in the parking lot and when I return, it’s still there. While one could argue that while I was inside, someone ran off with my car but someone else parked there in a car that looked just like mine, had the same stuff inside, and that my key fit in. Most likely though, it’s just my car still there, unmoved.
In other words, you don’t need to make up elaborate reasons to explain mundane things.
In a nutshell, it means the simplest route to your end is the best route. Very handy in geometry, not to mention criminology.
William of Occam was a middle ages philosopher who proposed that in order to correctly explain a situation one must “cut away” all of the excess leaving only the “core” explanation behind. The philosophical device where one explains a situation in the most simple terms is known as “Occam’s Razor.” It finds its greatest application in philosophy of science, and gets its greatest abuse in law (who ever saw a lawyer who was interested in reaching the simplest, most accurate answer for a situation?)
It’s in my dictionary too:
Oc•cam’s razor "a-kemz-\ noun [William of Occam] (ca. 1837)
: a scientific and philosophic rule that entities should not be multiplied unnecessarily which is interpreted as requiring that the simplest of competing theories be preferred to the more complex or that explanations of unknown phenomena be sought first in terms of known quantities
©1996 Zane Publishing, Inc. and Merriam-Webster, Incorporated. All rights reserved.
Uh oh. Joph and I have SIMILIAR responses, but not exactly the same. Time to hit Webster.
"A scienific and philosophical rule that entities should not be multiplied unnecessarily, which is interpreted as requiring that the simplest of competing theories be preferred to the more complex, or that explanations of unknown phenomena be sought first in terms of known quantities."
So, first my explanation, then Jophiel’s, and we’re both right. How nice.
Can’t we all just get along, Ike? 
Thanks to one and all!!
Ummm, a slight modification to jayron32’s post.
While it is true that Occam’s method “cuts away” the nonsense surrounding an explanation, my memory is that the epithet “razor” was supplied by William’s associates who said that he used his principle as a razor to slice up his opponents’ arguments.
William of Occam apparently stated his aphorism in several variants but the one I’m familiar with is “Non sunt multiplicanda entia praeter necessitatem.”, which translates as “Do not multiply entities unnecessarily.”
Be careful, however, because Mr. Occam’s fine razor is frequently misused. It is often paraphrased, more or less correctly, as “the simplest explanation is probably the right one”. So it is sometimes (mis)used by arguing that because my idea is simple it is therefore correct. Another misuse is to exclude certain aspects of what is being explained just so you can simplify your theory, and then invoke Occam’s Razor. (Other than that pesky ultraviolet catastrophe our understanding of blackbody radiation is just fine, thank you Herr Doctor Planck. We don’t need your confusing little theory.)
Bear in mind that it is not a logical “rule” whereby you can prove something is right or wrong. It’s just a way to choose between competing explanations. And it’s only one way to do so. A pretty darn good one, IMHO, but not the only one.
For example, in the middle ages it was simpler to believe that angels were moving the sun, moon and stars through the heavens than it was to imagine a theory of gravity with forces acting at a distance, etc, etc. Angels were familiar, simple entities. Why invent abstruse mathematical gibberish? In the (nearly) twenty-first century we think the math is simpler than the angels. Did the phenomena change? No, the sun and moon still move. Did Occam’s razor change? Nope. What changed? Our perception of what is simple, or unnecessary. IIRC, Thomas Jefferson, when he was told about the existence of meteors, replied something like, “I’d rather believe that a Yankee professor would lie than that rocks could fall from the sky.” A good use of the razor, I’d say, but it’s simpler for us, nowadays, to believe that rocks fall from the sky.