subject
Critical Thinking
How to evaluate arguments, weigh evidence, and notice the moves that good and bad reasoning have in common across very different topics.
13 lessons in critical thinking
Deductive and Inductive Reasoning: Two Modes of Inference
A detective stands over a body and announces the killer's name.
4 min · comparison
How Base-Rate Neglect Misleads
A doctor tells you that a screening test for a rare disease is 95% accurate.
4 min · deepening
How to Read a Statistic Without Getting Fooled
Imagine a headline that reads: "New study: people who eat breakfast are 40% less likely to be overweight." That number sounds solid.
3 min · foundation
How to Spot a Hidden Assumption
A friend tells you: "Maya runs every morning, so she must be in great shape." That sounds reasonable.
3 min · foundation
How to Spot a Hidden Assumption
Consider a short argument you might overhear in a coffee shop: "She went to a top law school, so she'll make a great judge." The sentence sounds reasonable, almost too obvious to question.
4 min · foundation
How to Spot a Slippery Slope
Imagine someone at your dinner table says: "If we let the school district change the start time by fifteen minutes, then parents will demand longer lunch periods, then they'll cut math class, then tes…
3 min · foundation
Opinion and Argument: Two Kinds of Claims
Two friends are arguing about a movie. One says, "That film was boring." The other says, "That film was boring because nothing changed for the main character — she wanted the same thing at the end tha…
3 min · comparison
What an Argument Actually Is — and Isn't
Two people are shouting at each other across a kitchen table. Their faces are red, the volume is rising, and someone watching might say they are having a heated argument. But listen to the actual sent…
4 min · foundation
Why Anecdotes Aren't Evidence
Your uncle swears he beat a bad cold by chewing raw garlic. He coughed all weekend, ate three cloves, and was fine by Monday. Now he tells everyone garlic cures colds. The story is vivid, it is true, …
3 min · deepening
Why Cherry-Picked Evidence Looks Convincing
Suppose someone hands you a folder containing twelve case studies of people who took daily cold showers and reported sharper focus, better mood, and fewer colds.
4 min · deepening
Why "Common Sense" Isn't Always Right
Drop a bowling ball and a marble from the roof of your school at the same instant.
3 min · foundation
Why Correlation Is Not Causation
In the summer of 1999, ice cream sales in New York City climbed sharply.
4 min · foundation
Why Smart People Believe Wrong Things
A puzzle sits at the center of modern psychology: the people most capable of reasoning carefully are not noticeably better at holding accurate beliefs about contested questions.
4 min · synthesis