Abstract

Karl Popper's well-known refusal of induction consists of three theses which have to be distinguished clearly: the thesis of deduction, the thesis of rationality, and the thesis of use. Whereas the first thesis is correct, the second thesis is pretty questionable and the third thesis is definitely false. It will be argued that Popper himself does not adhere to the second and third thesis consequently, insofar he thinks that practical induction is legitimate whereas theoretical induction is not. Further it will be shown that Popper's presentation of David Hume's thoughts on induction is inadequate.