Sharp rules. Steady bearings. Find your way when the trail fades.
Every day, we come to crossroads in our thinking. Most are small. Some can change the course ahead.
Philosophical razors are signposts we didn’t build, but can trust. They were shaped by long observation, hard mistakes, and the need to see what’s real from what only looks that way.
Here you’ll find old ideas worn smooth by time and new ones hammered out in the fire of modern life. Each is small enough to keep in your pocket, sharp enough to cut through the thicket of doubt.
They won’t choose the path for you. But they will clear the way so you can see the ground beneath your feet. Sometimes, that’s all it takes to keep moving.
Parsimony & Simplicity
- Occam's Razor: The simplest explanation with the fewest assumptions is preferred.
- Einstein’s Razor: Make things as simple as possible, but not simpler.
- Bacon's Razor: The more complex a theory, the more likely it is to be wrong.
- Thompson's Razor: The simplest explanation is often the most likely to be true.
- Kant’s Counter-Razor: Don’t rashly diminish the variety of beings. Moderation on parsimony.
- Chatton's Anti-Razor: If three causes aren’t enough to verify a claim, add a fourth.
Evidence & Burden of Proof
- Hitchens' Razor: What can be asserted without evidence can be dismissed without evidence.
- Sagan's Razor: Extraordinary claims require extraordinary evidence.
- Popper's Falsifiability Criterion: A theory must be testable and falsifiable.
- Alder's Razor (Newton's Flaming Laser Sword): What cannot be settled by experiment or observation is not worth debating.
- Hume's Razor: Causes must be sufficient to produce their effects.
- Hume’s Guillotine: You cannot derive what ought to be from what is.
- Russell’s Teapot: The burden of proof is on those making unfalsifiable claims.
- Shannon's Razor: Minimize unnecessary information in communication.
- Gell-Mann’s Razor: Assume every media article contains some false information.
- Grice's Razor (Principle of Charity): Interpret statements by the speaker's likely intent.
- Duck Test: If it looks, swims, and quacks like a duck, it probably is a duck.
Decision-Making & Productivity
- Naval’s Razor: If you can’t decide between two options, choose the harder one in the short term.
- Luck Razor: When choices are equal, pick the one that increases future opportunities.
- Discomfort Razor: Growth often lies in uncomfortable actions.
- Smart Friends Razor: If your most capable friends endorse something, pay attention.
- Lion Razor: Work in sprints, then rest.
- Listen Mode Razor: Listen more to learn from differences.
- Parkinson's Razor: Work expands to fill the time available.
- Laziness Razor: If a task can be done in a lazy way, do it that way.
Cautionary & Counter Principles
- Hanlon's Razor: Never attribute to malice what can be explained by stupidity.
- Hickam's Dictum: Patients can have as many diseases as they please.
- Crabtree's Bludgeon: With enough ingenuity, people can fit complex explanations to inconsistent data.
- Peter's Razor: In a hierarchy, people rise to their level of incompetence.
- Alder's Razor: If something cannot be settled by experiment or observation, it is not worthy of debate.
Counter-Razors & Cautions
- Chesterton's Fence: Don’t remove something until you know why it was put there.
Logic & Reasoning
- Morton's Fork: A false dilemma where contradictory observations lead to the same conclusion.
Medical & Diagnostic
- Sutton's Law: In diagnosis, check the most likely cause first.
- Zebra Principle: When you hear hoofbeats, think horses, not zebras.
Business & Networks
- Network Razor: If two quality people would benefit from knowing each other, make the introduction.
Emotional & Judgment
- Tarzwell's Razor: The more emotional you feel, the less you should trust your judgment.
- Grey's Law: Any sufficiently advanced incompetence is indistinguishable from malice.
Additional Principles
- Feynman's Razor: If you can’t explain something simply, you don’t understand it well enough.
- Knuth's Razor: Premature optimization is the root of all evil.
- Betteridge's Law: Any headline ending in a question mark can be answered with “no.”
- Cunningham's Law: The best way to get the right answer online is to post the wrong one.
- Godwin's Law: Online discussions will eventually involve Nazi comparisons.
- Poe's Law: Without clear indicators of intent, extremism and parody are indistinguishable.
Social & Psychological