The two fundamental problems of the theory of knowledge

In a letter of 1932, Karl Popper described "Die beiden Grundprobleme der Erkenntnistheorie - The Two Fundamental Problems of the Theory of Knowledge" - as '!a child of crises, above all of !the crisis of physics.

It asserts the permanence of crisis; if it is right, then crisis is the normal state of a highly developed rational science.' Finally available in English, it is a major contribution to the theory of knowledge and a major contribution to twentieth century philosophy.

Reporting in great detail on important research Popper carried out between 1930 and 1933, "Die beiden Grundprobleme der Erkenntnistheorie" was not published in German until 1979.

The two fundamental problems of knowledge that lie at the centre of the book are the problem of induction, that although we are able to observe only a limited number of particular events, science nevertheless advances unrestricted universal statements; and the problem of demarcation, which asks for a separating line between empirical science and non-science.

Popper seeks to solve these two basic problems with his celebrate theory of falsifiability.He argues that science is separated from on-science not by the verifiability but by the falsifiability of its theories.

He argues also that the inferences made in science are not inductive but deductive; science does not start out from observations and proceed to generalise them, as many presume, but start with problems, which it attacks with bold conjectures. "The Two Fundamental Problems of the Theory of Knowledge" contains the seed of many of the celebrated arguments that were later to find definitive expression in Popper's most celebrated work, "The Logic of Scientific Discovery".

It is therefore essential reading for anyone interested in Karl Popper, in the history and philosophy of science, and in the methods and theories of science itself.