Timothy Cleveland

The present paper explores three interrelated topics in Popper's theory of science: (1) his view of conjecture, (2) the aim of science, and (3) his (never fully articulated) theory of meaning. Central to Popper's theory of science is the notion of conjecture. Popper writes as if scientists faced with a problem proceed to tackle it by conjecture, that is, by guesses uninformed by inferential considerations. This paper develops a contrast between guesses and educated guesses in an attempt to show that there is more to scientific conjecture than conjecture. The suggestion is made that some inductive considerations enter into the process of educated guessing or scientific conjecture in such a way that the ‘context of discovery’ cannot be sharply separated from the ‘context of justification’. This discussion leads to a tension between Popper's negative method of conjecture and his realism. Given Popper's (implicit) theory of meaning it seems Popper's epistemology (the conjecture and refutation method) is incompatible with his metaphysical realism.