According to Lehrer’s defeasibility account of knowledge, we can understand knowledge as undefeated justified true belief. But this account faces many serious problems. One important problem is that from one’s subjective point of view, one can hardly bridge the gap between one’s personal justification and objective truth. Another important problem is that this account can hardly accommodate the externalist intuition that the epistemic status of a belief is not entirely determined by factors that are internal to the subject’s perspective. The (...) goal of this paper is to offer an alternative account of knowledge which can successfully deal with these problems. On the basis of a Sellarsian social practice theory of justification, I argue that we can understand knowledge as objectively justified belief. (shrink)