The metaphysical principle of the logical separation of "facts' and "values' has always been closely associated with positivistic philosophies. In the social sciences, however, its strongest and most influential advocate has been Max Weber, who derived it from Kant rather than from Hume. In Weber's writings, the implications of the fact/value dichotomy (or his version of it)¹ are rigorously traced out in respect of a series of problems; I shall treat here only those concerning the logical status of the differentiation of facts and values, and the relation of values within "calculi" or "hierarchies' of values.