When it comes to the mind-body problem, different kinds of physicalism were the most popular approaches among philosophers. The presence of anomalous monism with its lack of (the) laws concerning mental events and multiple realizability led to a doubt regarding reductionism and a slow movement away from it. It did not, however, weaken the popularity of physicalism. Thus, the problem that had to be faced was to create such a form of physicalism that would reject the reduction of what was (...) mental to what was physical. No difference of one sort without a difference of another sort is a slogan that expresses the idea of supervenience, the idea that according to many philosophers was supposed to be the right expression of physicalism of this particular type. The text briefly presents the intuitions that are hidden behind the notion of supervenience and its main varieties: weak, strong and global. Moreover, the text touches upon the fault of supervenience which was observed in its symmetry and, most of all, in its triviality. This type of fault would force the philosophers to admit that this relation is metaphysically irrelevant. (shrink)