Abstract
The aim of this paper is to show that the definition of a possible world in the actualist tradition of A. Plantinga, R.M. Adams, R. Chisholm, J. Pollock and N. Wolterstorff is unable to accomodate tensed states of affairs. An example of a tensed state of affairs is the transiently obtaining state of affairs that the storm is present, which obtains only if its negation, it is not the case that the storm is present also obtains but at different times. A possible world that includes tensed states of affairs and their negations cannot be defined in the traditional way, which states that a possible world is a state of affairs S that includes every state of affairs S' or (exclusive disjunction) the negation of S'. Rather, it must be defined in a new way: A possible world is a state of affairs S that includes every state of affairs S' or (inclusive disjunction) the negation of S', such that for every pair P of mutually contradictory tensed states of affairs entailed by S, the members of P obtain nonsimultaneously in S.