 Actualism  is the thesis that everything that there is, everything that has  being in any sense, is actual. In terms of possible worlds:  Everything that exists in any world exists in the actual   world.[32]  Possibilism, by contrast, is the denial of actualism; it is the  thesis that there are mere possibilia, i.e., things that are  not actual, things that exist in other possible worlds but fail to  exist in the actual world. Concretists are obviously not actualists  (on their understanding of ‘actual’, at any   rate).[33]  Indeed, for the concretist, since individuals are worldbound,  everything that exists in any nonactual possible world is distinct  from everything in the actual world. However, although possibilism  and abstractionism are entirely compatible — Zalta (1983), for  example, embraces both positions — abstractionists  tend to be actualists. The reason for this is clear: Basic  possible world semantics appears to be committed to possibilism and  abstractionism promises a way of avoiding that commitment. 