counterpart theory noun1 •An alternative to standard possible worlds semantics in which an individual can exist in only one world, while other possible worlds contain (different) counterparts to that individual, and in which the modality operators (necessity, possibility) are replaced by quantifiers over possible worlds.According to counterpart theory, Humphrey himself has the modal property, might have won the election, in virtue of his counterpart having the (non-modal) property, won the election. — 2013
