Thinking books · Knowledge & truth · Karl Popper, 1934
The Logic of Scientific Discovery — the big ideas
The argument that science proceeds by attempting to refute theories, not to confirm them.
Free — no account needed to read
The big ideas
No number of confirming observations proves a general claim, while one clear disconfirmation refutes it. That asymmetry is the whole structure of the argument.
Falsifiability marks the boundary: a theory compatible with every possible observation tells you nothing about the world.
A bold theory that forbids a great deal is more valuable than a cautious one that forbids little, because it is more testable.
Later philosophers dispute whether science works this way in practice. As a personal discipline it is still the single most useful check available.
Practise it — no need to have read it
Write a theory you hold about why something in your work happens. State what observation would refute it, then go looking for that.
A hint: Looking for the refutation rather than the confirmation is the entire discipline.
Where it shows up in real life
- Product hypotheses
- Diagnosing a problem
- Any explanation you are attached to
Described in our own words with the source named — never quoted, and not a substitute for reading the book.
Thinking methods from this book
- State what would refute it — Testing whether a claim is the kind of thing evidence could ever settle.
The thinking it builds
- Critical Thinking — Evaluate claims and evidence
- Logical Thinking — Reason consistently