It would be causal, that is, concerned with the conditions which bring bout belief of states of knowledge. Naturally there will be other types of causes apart from social ones which will cooperate in bringing about belief. It would be impartial with respect to truth and falsity, rationality or irrationality, success or failure. Both sides of these dichotomies will require explanation. It would be symmetrical in its style of explanation. The same types of cause would explain, say, true and false beliefs. In principle its patterns of explanation would have to be applicable to sociology itself. Like the requirement of symmetry this is a response to the need to seek for general explanations. It is an obvious requirement of principle because otherwise sociology would be a standing refutation of its own theories. Functionalist accounts explain scientific processes in terms of the kind of knowledge they produce.