 Second, it needs to be emphasized that these are intuitive semantic notions only. For not only are there well-known, formidable challenges to the notion of a world story that he does not  address,[86]  because Adams is a strict actualist, a formal, compositional semantics is simply unavailable to him, for the reasons noted in the  introduction to §4.3.  Hence, Adams’ talk of propositions being true in or at possible worlds cannot themselves be considered literally true but, as with similar talk from Prior, must simply be viewed as an evocative heuristic whose primary purpose is to motivate the basic logical principles underlying his variety of strict actualism.