Critical Thinking & Fallacies
Everything in the Logic track so far has been about what makes reasoning valid. This guide is about the opposite - and arguably more useful - skill: recognizing reasoning that is broken but doesn't feel broken. Because that's the dangerous kind. A bad argument that sounds bad fools no one. A bad argument that sounds great is how people get talked out of their savings, their vote, and their better judgment.
A fallacy is exactly that: an argument that's persuasive on the surface but logically unsound underneath. They're not rare or exotic - they're the everyday machinery of advertising, politics, and internet fights, and they work because they exploit feelings and mental shortcuts rather than logic. This guide gives you a name for each common one, an example so you'll recognize it in the wild, and a practical toolkit of clear-thinking habits. Naming a manipulation is the first step to being immune to it - and a person who can't be easily fooled can't be easily steered.
How to read this
- Want the catalog? Phase 2 is the field guide to the common fallacies.
- Want it to stick? Read in order - Phase 1 explains why fallacies work, Phase 3 is the toolkit that beats them.
The phases
- What a Fallacy Is (and Why They Work) - broken-but-convincing reasoning, and the psychology it exploits.
- The Fallacies You'll Meet Most - a field guide: ad hominem, straw man, false dilemma, slippery slope, post hoc, and more.
- Thinking Clearly: A Practical Toolkit - steelmanning, separating claim from evidence, cognitive biases, and verifying in the age of fluent AI.
This caps the Logic foundations. It draws on validity from What Logic Actually Is and the conditional errors from Implication & Conditionals.