<actualism, ontology, logic, potential, contingent> what really is the case, as opposed to what's possible (could be the case) and to what's necessary (must be the case); all of which are opposed to what's impossible (can't be the case). Concerning the latter "opposition": the categories possible and impossible are jointly exhaustive(everything is either one or the other). Concerning the former "opposition": necessity, actuality, and possibility are not mutually exclusive: everything necessary is also actual (what must be the case is the case) and everything actual is possible (whatever is possible). In other words, necessity entails actuality, and actuality entails possibility. (Also see contingent.)
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