Popper, Karl Raimund (1902-1994), was an Austrian-born philosopher whose central concern was analyzing the nature of science. In his major work, The Logic of Scientific Discovery (1935), Popper argued that science does not begin with the gathering of evidence through observation of the world. It begins with the formulation of scientific hypotheses (proposed explanations). The formulation of hypotheses is a creative act that precedes, shapes, and makes possible the gathering of any evidence. According to Popper, evidence is gathered only to test some already formulated hypothesis.
Popper wanted to mark the boundary between scientific and nonscientific accounts of the physical, psychological, and social world. Nonscientific accounts include those offered by astrology, mythology, and some forms of traditional philosophy and religion. This approach connects Popper with two overlapping philosophical movements, Logical Positivism and Empiricism. Philosophers representing these movements argue that meaningful scientific accounts differ from nonscientific ones in that only the scientific can be tested by experience.
In his popular work The Open Society and Its Enemies (1945), Popper argued that the admired philosophers Plato, G. W. F. Hegel, and Karl Marx were enemies of freedom because they laid the intellectual foundations for the totalitarian state.
Popper was born on July 28, 1902, in Vienna, Austria, and taught there until 1937, when he left the country because of the rise of the Nazis. He served as professor of logic and scientific method at the London School of Economics and Political Science from 1949 to 1969. Queen Elizabeth II knighted him in 1965, making him Sir Karl Popper. Popper died on Sept. 17, 1994.