Together with GodelsTheorem, BertrandRussell's idea of peer review, Popper's notion of falsifiability changed modern notions of proof and the ScientificMethod. Popper accepted Hume's critique of induction, taking the view that no matter how many times the same result occurs in an experiment there always remains the possibility that the next result will contradict this (as such truth assumes a provisional character). Under such circumstances a theory cannot be verified, merely assigned a truth value. However, the falsification of a theory may be regarded as conclusive whereas verification may not.
Popper is also noteworthy for having applied these observations beyond the realms of pure science. For example, communism had always described itself as being scientific, but was criticised by Popper for failing to pay heed to instances where its tenets had been falsified. Since communism failed to fulfill its predictions it has since fallen into the realm of belief - see OnCommunism. In particular, Popper regarded communist claims to predict social trends as being spurious. Since such events could not be predicted the only sensible approach is to proceed through continual scrutiny; to Popper the notions of democracy and rights can almost be considered as being analagous to peer review.
These ideas have proved extremely influential. The conservative social theorist MichaelOakeshott, applied scepticism to politics, seeking to exclude notions of certainty from that arena so that governments are restrained from imposing policies based on spurious notions of certainty. At the other end of the political spectrum, the postmodernist RichardRorty holds that since no interpretation of phenomena can lay claim to certain universality, a democracy accompanied by freedoms of speech is the most sensible approach. Finally, the economist FriedrichHayek took the view that since knowledge is limited and reason constrained, complex societies are not subject to prediction. In particular, attempting to predict social behaviour in advance of the individual decision is invalid since the the predicting agency may skew the results. This formed the backbone of Hayek's critique of socialism - see OnCommunism.
Popper has been considered for the post of VirianSaint for his implacable hostility to dogmatism and indeed for having provided the very intellectual framework which exposed its inadequacies. The Virian emphasis on ethics rather than morals reflects Popper's refusal to admit of certainty in such matters.
See also: PhilosophersAndBrigands, 
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