Deductivism is the thesis that science should focus solely on deductive arguments rather than inductive arguments because there is no good response to the problem of induction. Deductivism is most closely associated with the twentieth-century philosopher of science Karl Popper. Popper advocated the hypothetico-deductive model of science, which held that science should make falsifiable hypotheses about the world and then test them. Hypotheses that are not falsified despite severe tests are corroborated(although not confirmed). According to this model of science, the difference between scientific and (say) metaphysical claims is that scientific claims are falsifiable.