Karl Popper
Founder of falsificationism who redrew the boundary between science and pseudoscience with falsifiability
Karl Popper (1902-1994) was one of the most important philosophers of science and political philosophers of the 20th century, born in Vienna, Austria, and later moving to Britain. His falsificationism theory proposed "falsifiability" as the criterion distinguishing science from pseudoscience: a theory that cannot be refuted by any possible observation is not a scientific theory. This criterion allowed him to criticize Freudian psychoanalysis, Marxist historical theory, and Adlerian individual psychology as "pseudosciences." In political philosophy, his The Open Society and Its Enemies (1945) criticized the historicism and collectivism of Plato, Hegel, and Marx, becoming an important defense of liberal democracy. Popper "critical rationalism" — knowledge grows through a cycle of conjectures and refutations — deeply influenced scientific methodology, political theory, and investment philosophy (George Soros was his student).
Methodologies
- Falsifiability Checklist - Systematically test whether a theory or claim is falsifiable
- Open Society Audit - Assess whether an organization or institution allows critical discussion and error correction
Key decisions and timeline
- Einstein vs Freud: Starting Point of Falsificationism - The best theories are those that dare to make specific predictions that could be refuted — vagueness is not a virtue but a disguise.
- Publication of Logik der Forschung: Systematic Statement of Falsificationism - Critiquing the mainstream framework requires providing a better alternative, not merely pointing out defects.
- Exile to New Zealand: Thinking Political Philosophy Under the Shadow of Totalitarianism - Philosophical thinking is most urgent during political crises — abstract epistemological questions are directly connected to concrete political consequences.
Beliefs and mental models
- Belief 1 - Popper believed the hallmark of a scientific theory is not that it can be verified but that it can be falsified. "It might rain tomorrow" is a scientific statement (testable by observation); "all things have spirit" is not (cannot be refuted by any observation). Falsifiability gives scientific theories information content — they exclude certain possibilities.
- Belief 2 - Popper "critical rationalism" holds that scientific progress does not occur through induction (from observation to theory) but through deduction (propose conjecture → attempt to falsify → conjecture survives or is refuted → propose better conjecture). We can never prove a theory true, but we can prove it false — scientific knowledge is provisional and revisable.
- Belief 3 - Popper believed the "open society" is one that allows critical discussion and can reform institutions peacefully, in contrast to the "closed society" (authority based on myth, tradition, or historical necessity). His core political conviction: no theory or leader can claim to possess ultimate historical truth; institutions must allow for error correction.
- Model 1
- Model 2
- Model 3