Falsifiability

Karl Popper's criterion for distinguishing science from non-science: a theory is scientific only if it makes predictions that could, in principle, be PROVEN WRONG by observation. 'All swans are white' is falsifiable (finding one black swan refutes it). 'Everything happens for a reason' is NOT falsifiable (no observation could disprove it). Falsifiability doesn't mean the theory is false—it means the theory is TESTABLE. Unfalsifiable theories are irrefutable, which sounds strong but is actually weak: they can never be wrong because they never risk being tested. As a mental model: falsifiability is the gold standard for intellectual honesty—a claim that can't be proven wrong can't be taken seriously as knowledge, because it accommodates any possible evidence.

When to use it

When claims need evaluation for testability; when distinguishing between scientific and non-scientific assertions; when business hypotheses need pre-defined falsification criteria; when intellectual honesty requires specifying what would change your mind.

How it can help

For every important belief or theory: identify what evidence WOULD disprove it. If no evidence could disprove it, it's not a knowledge claim—it's a faith commitment or unfalsifiable assertion. The practices: (1) For your own beliefs: 'What would change my mind?' If nothing: you're holding the belief irrationally. (2) For others' claims: 'What evidence would prove you wrong?' If they can't answer: the claim isn't testable. (3) For business hypotheses: define failure criteria BEFORE testing. Without pre-defined falsification criteria, every result can be rationalized as supporting the hypothesis.