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SECTION 01 · 530 GUIDES

Concepts

Fundamental ideas, mental models, and frameworks for clear thinking. From first principles to systems theory, the concepts that shape how we understand the world.

WHAT YOU'LL FIND

Concepts are the building blocks of clear thinking. This collection draws on psychology, economics, philosophy, cognitive science and decision theory, the goal is not memorisation but internalisation.

  • Deep-dive explanations of thinking frameworks
  • Practical applications to real-world problems
  • Connections between related concepts
  • Evidence from research and expert practitioners

Browse by topic

11 TOPICS · SORTED BY SIZE

CONCEPT OF THE WEEK · 22 SEP 2026

Goodhart's law

When a measure becomes a target, it ceases to be a good measure. Named for economist Charles Goodhart's 1975 observation about monetary policy, generalised by Marilyn Strathern in 1997, it explains why call-centre handle times fall while customers get angrier, and why test scores rise while learning doesn't.

USE IT WHEN
Designing incentives, OKRs, dashboards, or any metric people will be judged on.
WHERE IT FAILS
Metrics that are the thing itself (revenue, deaths) don't decay when targeted; the law bites on proxies.

THREE GUIDES THAT APPLY IT

  1. 01Goodhart's Law Explained: When Measures Become TargetsPRINCIPLES & LAWS · 12 MIN
  2. 02Metrics That Lie: Designing Measurement Systems People Can't GameMETRICS & MEASUREMENT · 15 MIN
  3. 03The Cobra Effect and Other Perverse IncentivesSYSTEMS & COMPLEXITY · 11 MIN
Previous concepts of the week

Often confused

6 PAIRS · ONE-SENTENCE DISTINCTIONS

PSYCHOLOGY & BEHAVIOUR · 266 GUIDES

Bias & fallacy index

Every cognitive bias and fallacy we've covered, grouped by the kind of thinking it distorts. Each entry links to the guide that defines it, with sources.

Full index · 77 entries →

Latest in Concepts

GUIDES · NEWEST FIRST

Frequently asked questions

Simplified representations of how things work that help you predict outcomes, make decisions, and solve problems. Charlie Munger's “latticework” approach: learn fundamentals from many disciplines and you get a toolkit for better thinking across all of them.

Breaking a problem down to its foundational truths and reasoning up from there, instead of reasoning by analogy. It originates with Aristotle; Musk popularised it in business.

Seeing interconnections, feedback loops, delays, and leverage points rather than isolated events. Most real problems live inside systems where changing one part affects the whole.

Considering the consequences of consequences, asking “and then what?”, to reveal effects that first-order thinkers miss.

Reasoning with likelihoods and distributions rather than certainties. It acknowledges uncertainty and is essential for risk assessment, forecasting, and strategy.

Understand the core principle, recognise the patterns where it applies, practise deliberately across contexts, seek feedback, and build connections between related models.

Approach problems backward: ask how you would guarantee failure, then avoid those failure modes. Especially useful for risk management and strategy.

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