Piecemeal Social Engineering

Karl Popper

1902–1994 · Austria / United Kingdom

Karl Popper's life work crossed two domains — philosophy of science and political philosophy — and the same idea ran through both. In science, his argument (developed in The Logic of Scientific Discovery, 1934) was that what distinguishes a serious claim from an unserious one is whether it can be refuted by evidence. A theory that explains everything explains nothing. The growth of knowledge comes from putting our claims at risk and learning from the ones that fail.

In politics, Popper's target was utopian or 'holistic' social engineering — the attempt to redesign an entire society from blueprints, on the theory that comprehensive change is more effective than partial change. He had watched two such projects (fascism and Stalinism) consume Europe in his lifetime, and he argued in The Open Society and Its Enemies (1945) and The Poverty of Historicism (1957) that they were not merely tactically misguided but epistemically impossible. No designer can anticipate the cascade of effects in a system as complex as a society; the only honest method is what he called 'piecemeal social engineering' — small reforms, observable outcomes, the ability to back out.

Popper was not a defender of the status quo. He was a defender of being able to tell whether a change worked.

Why it matters here

Every civic experiment is a Popperian commitment. To run a pilot is to say in advance: here is the change, here is the population, here is the measurement, and here is what would convince us we were wrong. That commitment is what separates evidence-based policy from policy that merely cites evidence.

Karl Popper

Further reading