For some time now the philosophy of science has been undergoing a major transfor­ mation. It began when the 'received view' of scientific knowledge -that developed by logical positivists and their intellectual descendants - was challenged as bearing little resemblance to and having little relevance for the understanding of real science. Subsequently, an overwhelming amount of criticism has been added. One would be hard-pressed to find anyone who would support the 'received view' today. Yet, in the search for a new analysis of scientific knowledge, this view continues to exert influence over the tenor of much of present-day philosophy of science; in particular, over its problems and its