 As the names indicate, strong individual supervenience is stronger than weak individual supervenience. (We shall hereafter follow established usage and drop the word ‘individual’ unless clarity requires it.) Weak supervenience says that there is no possible world that contains individuals that are B-indiscernible but A-discernible. Strong supervenience entails that there are no possible individuals that are B-indiscernible but A-discernible, whether they are in the same world or different worlds. When the range of worlds is the same, strong supervenience theses entail weak supervenience theses, but the latter do not in general entail the former. It is important to note, however, that when A is restricted to intrinsic properties, strong and weak supervenience are arguably equivalent; see Section 4.3.4. 