 For Popper the central problem in the philosophy of science is that of demarcation, i.e., of distinguishing between science and what he terms “non-science” (e.g., logic, metaphysics, psychoanalysis, and Adler’s individual psychology). Popper is unusual amongst contemporary philosophers in that he accepts the validity of the Humean critique of induction, and indeed, goes beyond it in arguing that induction is never actually used in science. However, he does not concede that this entails scepticism and argues that the Baconian/Newtonian insistence on the primacy of “pure” observation, as the initial step in the formation of theories, is completely misguided: all observation is selective and theory-laden and there are no pure or theory-free observations. In this way he destabilises the traditional view that science can be distinguished from non-science on the basis of its inductive methodology. In contradistinction to this, Popper holds that there is no unique methodology specific to science; rather, science, like virtually every other organic activity, consists largely of problem-solving.