I say tools, but they’re actually called philosophical razors. 

A philosophical razor is a heuristic or principle for decision making. It can be used as a rule of thumb that allows you to “shave off” unlikely explanations or avoid unnecessary actions. 

Basically, they’re used to save you time.

Once you understand them, there are many practical uses for philosophical razors in everyday life. The razors that I will be discussing are:

• Occam’s Razor: Simpler explanations are more likely to be correct. Avoid unnecessary, over-complicated, or improbable assumptions.
• Hanlon’s Razor: Never attribute to malice that which can be adequately explained by stupidity.
• Hitchens’ Razor: “What can be asserted without evidence can be dismissed with evidence.”
• Sagan Standard: Extraordinary claims require extraordinary evidence.

The reasons for using these will vary, but the main reason that I use them is to make my life easier.

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Occam’s Razor

“The simplest solution is usually the best one.”

Occam’s Razor reminds us to stay away from overly complicated explanations. Let’s say there are two ways of doing something; one way requires three steps and the other takes ten. Assuming equality of outcome, the three-step option is likely the best. 

Fewer steps = simpler process = less chance of mistakes.

There’s a reason why the world isn’t teeming with Rube Goldberg machines.

What a fantastic little contraption this is! A machine that automatically wipes your face for you. Such a sensible device and not at all overdone!

But seriously. The simplest solution to wipe your face when it gets dirty is to pick up a napkin and wipe your face. Simple as that. It’s not that complicated, but sometimes we insist on it.

Here’s another scenario: You awaken to find your front door is wide open. 

There are several explanations for what’s happened. Maybe someone broke in. It’s possible that they broke into your house while you were sleeping, didn’t take anything, didn’t do anything, and left without a trace. 

Or, the much more likely and simpler explanation is that you simply forgot to shut it.

When in doubt, choose simplicity.

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Hanlon’s Razor

“Never attribute to malice that which can be adequately explained by stupidity.” 

Hanlon’s razor is the most widely applicable of the philosophical razors and it’s had the biggest impact on me personally. 

This is because it applies to many more motives than just stupidity. It can be stupidity, ignorance, selfishness, inability, or whatever else you want to tell yourself. The important thing is to avoid assuming malicious intent. This is important because when you assume malicious intent, the natural response is to take it personally and then respond with similarly bad intentions.

But so long as you can convince (or trick) yourself into thinking that it wasn’t done out of bad intentions, it doesn’t have to bother you as much.

The most powerful part about this concept is the main principle; transmuting one interpretation into another. You can change something that makes you angry to something that makes you sympathetic. Or take something that annoys you and turn it into motivation. Instead of becoming emotional, you can remain rational.

Perspective is extremely powerful. 

Using Hanlon’s Razor

My favorite example of this is driving and road rage. The best way to avoid getting angry while driving is to use Hanlon’s Razor to filter your perception. 

If you get cut off, your natural reaction is to think, “Why the **** did that dude just cut me off?” But if you can intercept that thought and replace it with, “Oh man, that dude must be running really late. Sucks to be him!” It may sound funny, but when you give yourself a reason to feel sympathetic, it’s much easier to avoid frustration. 

When you assume malice, on the other hand, you’re bound to take it personally. It’s only natural to become emotional and get offended. But when you chalk it up to stupidity or ignorance and realize that it’s not personal, it’s so much easier to handle. You can remain logical and not be sucked into the other driver’s mind games.

The most interesting part in my experience though is the power of the things we tell ourselves. It’s not nearly as difficult to trick yourself into believing something as you might think. Companies, advertising agencies, marketing specialists, and you are doing it all the time. And there’s a similar concept at play here. 

Going back to my driving example. Let’s say you get cut off and you’re pretty sure it’s on purpose. You can still override that belief and just tell yourself that it was probably an accident. You may be surprised by how effective this can be. 

Even in the example of someone cutting you off while simultaneous cursing and flipping you off, you don’t have to take it personally. Maybe they think you’re someone else. Maybe they’re confused. Maybe they’re just not well in the head. Who knows. 

A friend of mine likes to frame it as a power struggle. He’s able to remain calm and not give in to other people by reminding himself that by playing their games, he’s giving up control of his actions. He’s letting the other person hijack his thoughts and experience and turn him into something he’s not. Apparently, that thought works well enough for him because I’ve never seen him even remotely road raged.

Never let bad actors control how you think or act. 

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Hitchens’ Razor

“What can be asserted without evidence can be dismissed with evidence.” 

This one’s important.

“It says that the burden of proof lies with the one who makes the claim; if this burden is not met, then the claim is unfounded, and its opponents need not argue further in order to dismiss it.”

If someone walks up to you and tells you that ghosts are real, it’s their responsibility to prove it. It’s not your responsibility to disprove any given assertion that another person makes. 

It’s like a principle of reciprocity – your response gets to match their assertion. If they don’t provide any evidence, neither should you.

So basically, if someone is trying to convince you of something but can’t provide any sort of proof, you shouldn’t feel bad about dismissing them.

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Sagan Standard

“Extraordinary claims require extraordinary evidence.” 

Named after legendary astronomer Carl Sagan, the Sagan Standard is very similar to Hitchens’ Razor, but I still wanted to mention it. The Sagan Standard points out that the burden of proof lies with the party making the assertion. 

If someone walks up to you and tells you that aliens are real, well that’s a pretty extraordinary claim. So we’re going to require some pretty extraordinary evidence.

Unlike Hitchens’ Razor, theories of extraterrestrial life should be enough to dissuade you from dismissing this claim due to a lack of evidence. Astronomers estimate there are about 100 thousand million stars in the Milky Way galaxy alone. And that’s just one of the billions of other galaxies out there.

Now, that is an extraordinary claim, but astronomers have provided some pretty extraordinary evidence.

The number of possibilities would make it irresponsible to just write off as untrue. But along the same line, we’ve also yet to prove it.

Conclusion

“Well, the first rule is that you can’t really know anything if you just remember isolated facts and try and bang ’em back. If the facts don’t hang together on a latticework of theory, you don’t have them in a usable form. You’ve got to have models in your head. And you’ve got to array your experience both vicarious and direct on this latticework of models. You may have noticed students who just try to remember and pound back what is remembered. Well, they fail in school and in life. You’ve got to hang experience on a latticework of models in your head.”

-Charlie Munger

These four philosophical razors are examples of mental models. They’re ideas, heuristics, and rule of thumbs that are like lenses that we can view situations through. You don’t always have to use them. And overusing them will also likely backfire.

Beware of the Law of the Instrument aka Maslow’s Hammer which roughly states, “To a man with a hammer, everything looks like a nail.”

The whole idea is to have them as tools on your tool-belt. 

Given the appropriate situation, you’ll be well prepared. 

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That’s it for this one! I hope enjoyed it. If you’re interested in learning more heuristics and mental models, check out Farnam Street Blog‘s master list here (it’s amazing!): https://fs.blog/mental-models/

Were you already familiar with these ideas? Are there any other mental models that you find useful? Let me know in the comments!

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Thanks for reading!