  Possible worlds are then defined as special cases of the type of entity in question that are in some relevant sense total. Adams (1974), for example, defines possible worlds to be consistent sets of propositions that are total in the sense of containing, for every proposition p, either p or its negation; Fine (1977), fleshing out ideas of Prior, defines a possible world to be a consistent proposition w that is total in the sense that, for every proposition p, w entails either p or its negation. For purposes here, however, we will sketch the fundamentals of the abstractionist view in terms of states of affairs, following the basic features of the account developed by Plantinga (1974, 1976), an account that, in the literature, frequently serves as a particularly trenchant abstractionist counterpoint to Lewis's concretism.[27] 