In On Certainty, the emphasis is on the solitary individual as subject of knowledge. The importance of our dependence on others, however, is brought out in Wittgenstein's remarks about trust. In this paper, the role and nature of trust are discussed, the grammar of trust being contrasted with that of reliance. It is shown that to speak of trust is to speak of a fundamental attitude of one person towards others, an attitude which, unlike reliance, is not to be explained, (...) or assessed, by an appeal to reasons. It is, rather, because we have such a fundamental readiness to accept what we are taught by others that we can come to develop an understanding of reasons. The idea that believing something without evidence is always a weakness is shown to be a philosophical prejudice. Trust is always for something we can rightfully demand from others: misplaced trust, accordingly, is not a shortcoming on the part of the trustful person, but of the person in whom the trust was placed. The destruction of trust is a tragedy of life; in Culture and Value, Wittgenstein suggests a connection between distrust and madness. (shrink)