Occam’s Razor 👨🏻🎓 Explained
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Explaining Occam’s Razor & a little background on where it comes from, and provide some examples to help get a better grasp of this mental model.
Occam’s Razor is a philosophical razor that states, entities should not be multiplied beyond necessity. It is often paraphrased today as, the simplest explanation is usually the best one. It is also known as the Law of Parsimony.
Occam’s Razor is a philosophical razor that states, entities should not be multiplied beyond necessity. It is often paraphrased today as, the simplest explanation is usually the best one. It is also known as the Law of Parsimony.
Parsimony is just a ten-cent word that means to be extremely thrifty or careful with resources. Occam’s Razor is parsimonious in that it says we should look for the simplest explanations when in search of the truth.
Explaining Occam’s Razor
Occam’s Razor works as a rule of thumb that can be used when you’re faced with a number of competing explanations for a given situation or phenomenon. It says that the simplest explanation is usually the best one, or conversely, that unnecessarily complex and convoluted explanations are unlikely to be correct. It advocates for simplicity, or parsimony, and helps you choose the most likely explanation by eliminating those that are needlessly complex.
Occam’s Razor works as a rule of thumb that can be used when you’re faced with a number of competing explanations for a given situation or phenomenon. It says that the simplest explanation is usually the best one, or conversely, that unnecessarily complex and convoluted explanations are unlikely to be correct. It advocates for simplicity, or parsimony, and helps you choose the most likely explanation by eliminating those that are needlessly complex.
But why is it called a “razor”? What is a philosophical razor?
In philosophy, a razor is a principal or rule of thumb used to shave away unnecessary ideas or theories.
Other notable philosophical razors include Hanlon’s Razor and Hume’s Guillotine. Each one of these applies a principal or rule of thumb to eliminate unlikely options, arguments, or ideas. And that’s exactly how Occam’s Razor works. It’s a rule of thumb used to cut away less likely explanations.
I’ll give you an example of Occam’s Razor in action in just a minute. But first, let’s talk about where this philosophical razor gets its name.
In philosophy, a razor is a principal or rule of thumb used to shave away unnecessary ideas or theories.
Other notable philosophical razors include Hanlon’s Razor and Hume’s Guillotine. Each one of these applies a principal or rule of thumb to eliminate unlikely options, arguments, or ideas. And that’s exactly how Occam’s Razor works. It’s a rule of thumb used to cut away less likely explanations.
I’ll give you an example of Occam’s Razor in action in just a minute. But first, let’s talk about where this philosophical razor gets its name.
About William of Ockham
Occam’s Razor is named after William of Ockham, a 14th century Franciscan Friar, theologian, and scholastic philosopher. He was born in the town of Ockham, located in Surrey, England and attended Oxford.
William spent six years at Oxford and did enough work to be granted his masters, but for reasons we don’t know, he never received that honor. Regardless, William went on to teach and write and is a major figure in medieval thought, having produced important works on logic, physics, and theology.
In fact, he was often at the center of the significant intellectual and political controversies of his day, and even went as far as to publicly call Pope John 22 a heretic. Unsurprisingly, in hindsight at least, Williamof Ockham was eventually excommunicated from the Roman Catholic Church.
What’s interesting about Occam’s Razor is that William of Ockham didn’t really invent it. Aristotle, Ptolemy, Aquinas, and Duns Scotus all promoted the law of parsimony, which is what Occam’s Razor is, well before William of Ockham.
An example of Occam’s Razor in use
Okay! So we’ve covered how Occam’s Razor works, explained philosophical razors, and talked about William of Ockham’s background. Now it’s time for an example.
Let’s say you live in an apartment building in NYC that’s next to a railway line. As you’re watching television, a loud rumble overwhelms you. Is that loud noise a train going by or is it a herd of African water buffalo stampeding on the street below?
The simplest explanation is that it’s a train.
Okay! So we’ve covered how Occam’s Razor works, explained philosophical razors, and talked about William of Ockham’s background. Now it’s time for an example.
Let’s say you live in an apartment building in NYC that’s next to a railway line. As you’re watching television, a loud rumble overwhelms you. Is that loud noise a train going by or is it a herd of African water buffalo stampeding on the street below?
The simplest explanation is that it’s a train.
A caution for using Occam’s Razor
I must caution you that it’s possible to oversimplify and end up with the wrong answer.
For example, someone might go to the doctor with flu-like symptoms: headache, sore joints, and a fever. The doctor, using Occam’s Razor, might conclude they’ve got the flu, since that’s the simplest explanation. But, it’s possible that further tests might reveal a more serious problem, like Lime Disease.
The two things to keep in mind if you want to avoid misapplying Occam’s Razor is first, remember it’s just a rule of thumb, and not a law. Second, always get as much information as you can before eliminating possible options. Keeping these things in mind will help you avoid jumping to the wrong conclusion.
For example, someone might go to the doctor with flu-like symptoms: headache, sore joints, and a fever. The doctor, using Occam’s Razor, might conclude they’ve got the flu, since that’s the simplest explanation. But, it’s possible that further tests might reveal a more serious problem, like Lime Disease.
The two things to keep in mind if you want to avoid misapplying Occam’s Razor is first, remember it’s just a rule of thumb, and not a law. Second, always get as much information as you can before eliminating possible options. Keeping these things in mind will help you avoid jumping to the wrong conclusion.
Conclusion
So, there you have it! Occam’s Razor, named after William of Ockham, is a philosophical razor that states the simplest explanation is often the best one. It’s a rule of thumb that’s best applied to eliminate unlikely explanations after you’ve reasonably collected as much data as possible.
Occam's Razor Explained &
How it Differs from Other Rational Principles
This
is a video explaining Occams's Razor, which is a normative, rational
pattern of thought. It also explains how this principle differs from Inference to
the Best Explanation and some other similar principles. There is also
an explanation of an individual's ontology. To illustrate all of this,
several examples are used involving the germ theory of disease and plate
tectonics. This video was originally developed for use in an
introductory level philosophy course, Introduction to Ethics, but it can
be used for any philosophy course.
Comments Amazing explanation of Occam's razor. I was teaching my students about Occam's razor and needed to check my own understanding of what it really means. I read a few notes about it and browsed on YouTube to find out more. Found some but nothing as helpful as yours. You have helped me beyond what I already knew ( or thought I knew ) . Explaining how we choose the simplest solution based on our ontology makes so much sense. I also love the examples using the continents because it shows the choices we make in our explanation. Thank you.
Thanks for the more detailed explanation. I originally heard the term in Carl Sagan's PBS series Cosmos and then again in the movie Contact.
P.S. I used it in trying to figure out how you're writing backwards on a glass board. I initially thought you're either a genius who can see this in his head and transfer it to the board for us to be able to read it, or that you're really not left-handed and that you probably just inverted the video image. Because most people are right-handed I assumed the ladder. Yes?
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The best presentation on YouTube on "Occam's razor". from 0.20 to 6.00 minutes. What clarity man! Many thanks. You deserve a standing ovation! This video is an absolute must for all PhD students
1. Every human possess an ontology model deep inside his mind
2. Formal education must help every man to digout-clarify his own ontology model
3. else... !
4. All expenditure on education in terms of money-time-efforts will go waste
1. Every human possess an ontology model deep inside his mind
2. Formal education must help every man to digout-clarify his own ontology model
3. else... !
4. All expenditure on education in terms of money-time-efforts will go waste
5. As man becomes older , he must attempt to simplify his own ontology model as much as possible
6. He must document-publish it before he dies !
7. He must pass it on to the next generation as legacy.
6. He must document-publish it before he dies !
7. He must pass it on to the next generation as legacy.
The Occam’s Razor In A Nutshell
Occam’s Razor states that one should not increase (beyond reason) the number of entities required to explain anything. All things being equal, the simplest solution is often the best one. The principle is attributed to 14th-century English theologian William of Ockham.
Understanding Occam’s Razor
Occam’s Razor is a principle that states that one should not increase (beyond reason) the number of entities required to explain anything. In other words, with all things being equal, the simplest solution is often the best one. The principle is attributed to 14th-century English theologian William of Ockham.
It’s important to realize that Occam’s Razor is not 100% reliable. That is, the simplest solution is not always the correct solution. But when presented with several solutions to a problem, its best course of action is to choose the solution with the fewest assumptions.
Understanding Occam’s Razor
Occam’s Razor is a principle that states that one should not increase (beyond reason) the number of entities required to explain anything. In other words, with all things being equal, the simplest solution is often the best one. The principle is attributed to 14th-century English theologian William of Ockham.
It’s important to realize that Occam’s Razor is not 100% reliable. That is, the simplest solution is not always the correct solution. But when presented with several solutions to a problem, its best course of action is to choose the solution with the fewest assumptions.
What is Occam's Razor?
A famous but often misunderstood principle in philosophy, how we can use this principle to help guide us in choosing appropriate models and theories.
Occam refers to William of Ockham, a 14th century English logician and theologian. A “razor” in philosophy is a guiding principle that helps philosophers “shave away” unlikely or unuseful explanations for a phenomenon. In the case of Occam’s razor, overly complicated explanations are shaved away. More directly, if two competing explanations, theories, or models explain the same phenomenon equally well, philosophers generally prefer the explanation that makes the fewest assumptions. William of Ockham was not the first to propose such a principle, as it was famously used by Aristotle, St. Thomas Aquinas, and other philosophers before him. He did, however, use the principle in much of his philosophical work, and thus the razor became associated with him.
It is important to note that Occam’s razor does not make any claim about which of two competing theories is actually true, or which will continue to explain the phenomenon as new data is uncovered. Rather, it is a rule of thumb that guides scientists and philosophers when developing and choosing between models and theories. It is particularly effective against the tendency to add assumptions (called ad hoc hypotheses) to an older theory to make it fit with new conflicting evidence.
A good example of Occam’s razor at work concerns the debate between the geocentric and heliocentric models of the solar system. The goal of both models was to explain the motion of the planets as seen from earth. The geocentric model began with each planet following a simple orbit around the earth. However, it was later observed that the inner planets did not simply move across the sky but danced with the sun in a complicated pattern. The outer planets even appeared to turn around and move backward for a brief period in their orbit, before continuing through the sky. Furthermore, the planets moved at different speeds throughout their path. The geocentric model used ad hoc hypotheses to account for these new observations, assuming that the planets orbited on epicycles which themselves orbited the earth, or rather, a point very close to the earth, and that their speed was constant about a third point slightly farther from the earth. When still more discrepancies were observed, more epicycles were added until the model was thoroughly over-complicated. Meanwhile, the heliocentric model more elegantly explained all the observed phenomena by assuming all planets move in elliptical orbits around the sun. Occam’s razor supports this model, which continues to explain newly observed stellar phenomena even today.
There are many other instances in which Occam’s razor supported a successful scientific theory. For example, quantum mechanics and special relativity were both huge departures from previous theories in an effort to avoid extraneous or ad hoc hypotheses. Even before the empirical success of Occam’s razor, the idea drew support due to its aesthetic appeal. St. Thomas Aquinas, Newton, and Galileo all remarked that simplicity was inherently natural and desirable, and physicist Paul Dirac believed that theorists should strive for the mathematical beauty that often accompanies simplicity. Scientists and philosophers alike agree that all theories must be understandable and testable to be successful, therefore pragmatically speaking a model with fewer assumptions and complications is easier to work with. While opponents of Occam’s razor argue that it is subjective and stifles creativity, its successes have earned it a place as a cornerstone of modern philosophy and scientific thinking.
It is important to note that Occam’s razor does not make any claim about which of two competing theories is actually true, or which will continue to explain the phenomenon as new data is uncovered. Rather, it is a rule of thumb that guides scientists and philosophers when developing and choosing between models and theories. It is particularly effective against the tendency to add assumptions (called ad hoc hypotheses) to an older theory to make it fit with new conflicting evidence.
A good example of Occam’s razor at work concerns the debate between the geocentric and heliocentric models of the solar system. The goal of both models was to explain the motion of the planets as seen from earth. The geocentric model began with each planet following a simple orbit around the earth. However, it was later observed that the inner planets did not simply move across the sky but danced with the sun in a complicated pattern. The outer planets even appeared to turn around and move backward for a brief period in their orbit, before continuing through the sky. Furthermore, the planets moved at different speeds throughout their path. The geocentric model used ad hoc hypotheses to account for these new observations, assuming that the planets orbited on epicycles which themselves orbited the earth, or rather, a point very close to the earth, and that their speed was constant about a third point slightly farther from the earth. When still more discrepancies were observed, more epicycles were added until the model was thoroughly over-complicated. Meanwhile, the heliocentric model more elegantly explained all the observed phenomena by assuming all planets move in elliptical orbits around the sun. Occam’s razor supports this model, which continues to explain newly observed stellar phenomena even today.
There are many other instances in which Occam’s razor supported a successful scientific theory. For example, quantum mechanics and special relativity were both huge departures from previous theories in an effort to avoid extraneous or ad hoc hypotheses. Even before the empirical success of Occam’s razor, the idea drew support due to its aesthetic appeal. St. Thomas Aquinas, Newton, and Galileo all remarked that simplicity was inherently natural and desirable, and physicist Paul Dirac believed that theorists should strive for the mathematical beauty that often accompanies simplicity. Scientists and philosophers alike agree that all theories must be understandable and testable to be successful, therefore pragmatically speaking a model with fewer assumptions and complications is easier to work with. While opponents of Occam’s razor argue that it is subjective and stifles creativity, its successes have earned it a place as a cornerstone of modern philosophy and scientific thinking.
William of Ockham was a theologian in the 14th century and most of you will likely be familiar with Occam’s razor, but for those of you that are not, it can be summarised as follows: Given conflicting theories, the one with the fewest assumptions, is more likely to be correct. It’s so named because it cuts away that which is unnecessary. ‘The Razor’ by Richard and Jordan tells Ockham’s tale in the most stunningly beautiful way.
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