A toolkit of thinking shortcuts the smartest people reuse — each one explained with a real example. Learn them to make sharper decisions, spot flawed arguments (including your own), and explain your reasoning in a sentence.
A **mental model** is a reusable way of thinking — a lens that helps you understand a situation and decide what to do. You already use some without naming them: supply and demand, cause and effect, incentives. The trick is to collect *good* ones from many fields — physics, biology, economics,…