Home – Home – Jornals – Philosophy of Sciences 2022 number 1

The contextual definition of knowledge proposed by D. Lewis does not solve the Gettier problem. Rather, the problems which Lewis’s approach faces indicate that a satisfactory epistemological theory must accept the primacy of knowledge and the equivalence of knowledge and evidence, which leads to T. Williamson’s knowledge first epistemology. The rules which Lewis introduces for determining the relevant possible scenarios and which should be taken into account in his approach to knowledge are ad hoc . In particular, Lewis admits that he does not know how to reformulate the resemblance rule, so as to exclude the scenario of radical skepticism in a way that is not ad hoc . As a general principle for Lewis’s rules, we propose the principle of family resemblance, understood as the existence of a common Wittgensteinian rule and, in particular, the existence of common hinge propositions. Adjusted accordingly, Lewis’s definition of knowledge is compatible with both Wittgenstein’s hinge epistemology and Williamson’s knowledge first approach.