Person
Karl Popper
Vienna-born philosopher of science (1902–1994), known for the criterion that a scientific theory must be falsifiable.
Biography
Karl Popper was born in Vienna on 28 July 1902 and died in 1994. He is one of the most discussed names in the philosophy of science. His answer to the question of how to separate science from non-science is falsifiability: a theory is scientific if it could be incompatible with some possible observation.
He illustrated this by comparing Einstein’s risky predictions with psychoanalytic accounts that fit any human behaviour. In his view theories are never conclusively verified; they are only corroborated by surviving tests. He also accepted that changing auxiliary hypotheses is respectable scientific practice as long as it yields new testable predictions.
His main work, Logik der Forschung, appeared in Vienna in 1935; the English translation, The Logic of Scientific Discovery, followed in 1959. Thinkers such as Kuhn, Lakatos and Putnam criticised his ideas, and those criticisms became one of the central debates of the philosophy of science.
In this course
Testability, the first question in judging a theory, is treated in this lesson (What Is a Theory? Paradigms and Classifications) with his criterion.
Key works
- Popper, Karl R. (1959 [1935]). The logic of scientific discovery. London: Hutchinson. — The source of the falsifiability criterion; original title Logik der Forschung (1935).