Popper, Karl Raimund

Born July 28, 1902, in Vienna. Austrian and British neopositivist philosopher, logician, and sociologist.

Popper was close to the Vienna circle. He moved to Great Britain in 1945 and was a professor of logic and scientific method at the University of London from 1949 to 1969. He served as dean of the faculty of philosophy, logic, and scientific method at the London School of Economics and Political Science from 1945 to 1969.

Although Popper’s philosophic conception, which he called critical rationalism, is close to logical positivism, Popper is critical of some of the basic principles of the latter. Popper thinks that philosophy should chiefly seek to elaborate the logical foundations of scientific methodology. His views of the nature of science are contradictory. On the one hand he criticizes doctrines that view universal laws and theory as rules or a totality of instructions for deriving one set of singular statements from another and declares that science deals with objective phenomena and is capable of real discoveries; on the other hand he denies that science attains the truth. Rejecting the Vienna circle’s principle of verification (empirical confirmation), Popper proposes the principle of falsifiability as a methodological principle with which to separate scientific knowledge from speculative metaphysical conjectures. According to the principle of falsifiability, the categorization of theories and statements as scientific knowledge is determined by the possibility of refuting the theories and statements empirically. Popper contends that science develops when bold hypotheses are advanced and various methods of refutation are attempted. The more corollaries one can derive from a hypothesis to refute the hypothesis empirically, the richer the hypothesis is in content. Popper inconsistently declares to be irrefutable and basic those statements of science that competent observers recognize to be well-founded and not in need of further verification.

In logic, Popper is known for his works in probability logic and the theory of derivability. In sociology, Popper sharply opposes determinism and historicism, especially Marxist historicism, and rejects the possibility of a scientific theory of historical development. To counterbalance this, he calls on sociology to plan concrete social changes with the aid of fragmentary social engineering. An apologist of bourgeois democracy, Popper regards this social system as “open” and humane; to it he opposes “totalitarian” and “closed” societies, among which from an anticommunist standpoint he includes socialist society.