You've encountered these ideas without knowing their names.

Your friend won't accept any evidence against their conspiracy theory? That's Popper's razor. Social media makes you want things you didn't want before? That's Girard's razor. Politicians promising solutions with no downsides? That's what Sowell's razor cuts through.

A "razor" in philosophy is a mental tool that cuts away bad thinking. Occam's Razor. Hanlon's Razor. Hitchens's Razor.

Twenty Razors gives you twenty more—from history's sharpest minds.

Each thinker gets:

• Their core insight — what they actually argued, not the cartoon version
• Blindspots — where they got it wrong or overstated their case
• Why it matters now — how the idea shows up in today's debates
• The razor — a practical test to apply the concept yourself

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THE TWENTY

The Classics: Socrates, Machiavelli, Kant
The Economists: Adam Smith, Marx, Hayek, Keynes, Friedman, Sowell
Modern Minds: Popper, Arendt, Foucault, Girard, Kahneman, Taleb, Haidt, Henrich
New Voices: Caplan, Henderson

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CONCEPT CARDS

Go deeper on specific ideas: the knowledge problem, categorical imperative, mimetic desire, luxury beliefs, skin in the game, banality of evil, and more.

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QUIZ YOURSELF

Test your understanding. Each question includes "cope explanations"—why the wrong answers feel right.

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WHO THIS IS FOR

• Curious people who want frameworks for understanding the world
• Those who encounter ideas in debates and want the full picture
• Anyone allergic to academic jargon and textbook padding
• People who'd rather spend 10 minutes than 10 hours

No internet required. No ads. No tracking. Just ideas.

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