In his The Logic of Scientific Discovery (1935; English translation, 1959), Popper (1902–1994) attacked the logical positivist assumption that scientific hypotheses could be derived from experience and confirmed by it inductively. Popper claimed that hypotheses can never be completely confirmed because we can’t know what the future will hold with certainty, or even with high probability. It requires an unspecifiably high number of positive instances to confirm a hypothesis and only one negative case to falsify or discredit it. Popper’s theory of falsification was very well received by working scientists.