Suppose psychological states supervene on physical states.
If, however, these are each genuine possibilities, facts about the identity of persons over time do not supervene upon any physical or psychological facts.
According to Tuomela, actions by collectives supervene on the actions of the operative members of the collective in such a way that the properties of particular collectives, such their intentions, beliefs, and desires, are "embodied in" and "determined by" the perspectives of the properties of individual members or representatives of the collective in question (Tuomela 1989, p. 494).
Indeed, many such views will even endorse stronger principles, such as that the chances supervene on the physical properties of the trial device alone, or that the chance depends on some particular dispositional property of the chance setup (as in propensity theories).
Among the common variants are those that take conscious reality to supervene on the physical, be composed of the physical, or be realized by the physical.
If this inverted spectrum hypothesis is correct, then qualia do not supervene on representational properties, and therefore representationalism is false.
Nor can it be said that she denies that facts about life reduce to (or supervene on, if you like) microphysical facts.
Thus we should distinguish what is standardly known as 'haecceitism' (roughly, the view that there may be bare identities across possible worlds in the sense of identities that do not supervene on qualitative properties) from the belief in haecceities (the belief that individuals have unanalysable non-qualitative properties that constitute their being the individuals that they are).
So it is quite empty to say that the modal facts about which propositions are contingent supervene on some more natural, non-modal facts.
Blackburn's favored explanation of the difference in status between the two claims is roughly as follows: Moral judgments must supervene on judgments regarding natural properties because it is the point of moral judgments "to guide desires and choices among the natural features of the world" (Blackburn 1993, 137).
But they do supervene on properties of things, those "qualities in objects," which are fitted by nature to produce the particular feelings.
