Occam's Razor as a Scientific Principle

Lesson Transcript
Instructor: Artem Cheprasov

Artem has a doctor of veterinary medicine degree.

Occam's razor as a scientific principle states that the simplest explanation is the one that is mostly likely correct. Learn about Occam's razor, how it applies to conspiracy theories, a life example of Occam's razor, and a scientific example of Occam's razor. Updated: 10/06/2021

Conspiracy Theories

JFK, 9/11, the moon landing, the Bermuda Triangle, and a ton of other stuff have something very much in common. They all have competing conspiracy theories trying to explain what happened and why. Multiple shooters, inside jobs, Hollywood fakes, and UFO abductions, just to name a few.

Conspiracy theories are faulty, not only because they completely disregard factual evidence proving them false but also because of a principle we'll be delineating in this lesson. If conspiracy theorists only followed this simple principle, they wouldn't waste their time on their convoluted and overly complex (not to mention unprovable) explanations of what, oftentimes, has already been explained. This principle is known as Occam's razor.

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  • 0:01 Conspiracy Theories
  • 0:53 Occam's Razor
  • 2:06 A Life Example of…
  • 3:24 A Scientific Example…
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Occam's Razor

William of Ockham, also spelled with two 'c's' instead of a 'k,' was a Franciscan philosopher who was born in 1285. He was famous for what I just mentioned, Occam's razor. This is a philosophical principle that, in its original form, states, 'Plurality should not be posited without necessity.' That definition is one reason why I don't like reading most historical philosophical writing, or at the least, their translations. They make things sound more complicated than they need to be.

Since simple explanations of the same thing are better than complex ones, let me put Occam's razor for you another way. In simple person speak, Occam's razor says that when there are two competing theories that make the same predictions or reach the same conclusion, the simple theory is better. Or, to put it in an even simpler way, the simplest explanation of some sort of observation in nature is the one that is most likely to be correct. That's the principle of Occam's razor. The reason the word razor is used is because we use this principle to shave away extraneous details from an explanation for something.

A Life Example of Occam's Razor

Conspiracy theories aside, let us look into a couple examples of Occam's razor to help further explain this concept: one example from normal life and one related to science. Let's say that you came home one day and found that the stove was on. This surprises you since you're normally very diligent about not forgetting to turn it off. One explanation for this is that you left it on after cooking earlier and simply had a brain lapse, even if you don't want to admit to it.

Another explanation may be that someone broke into your home while you were gone and turned the stove on, so it's not your fault the stove is on. The second explanation means someone had to know how to pick your door lock, disarm your alarm system, avoid detection by neighbors, clean up any evidence of entry such as fingerprints, turn the stove on, and leave just as quietly without being detected. Not to mention, you have to come up with some sort of motivation for this intruder to do such a thing.

The first explanation only requires a brain lapse and a lack of action on your part to turn the stove off. Therefore, in the absence of any evidence to the contrary, the first explanation is the simplest and the one that is most likely to be correct.

A Scientific Example of Occam's Razor

From a scientific standpoint we can apply the same principle to explanations of retrograde motion of the planets. This is the apparent backwards motion of a planet against the background of stars. Imagine you're on a circular racetrack, riding in a really fast car. You know that everyone on the racetrack is moving forwards in the same direction. But since you are going really fast, as you overtake slower cars, they appear to move backwards, away from you. Clearly, they are not doing this, but because you are moving faster than they are, it seems to be so.

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