Descartes’ reply to these objections involves the notion of a “true and immutable nature” (“TIN”) (AT 7.101ff.). Only some of our ideas of things that have TINs. Moreover, TINs themselves exist in some way, although they need not exist in concrete or empirical reality. Perhaps they are abstract objects, like numbers or sets (Descartes explicitly compares them to Plato’s Forms). In any case, the kind of existence TINs have is sufficient to undermine the second objection above: the divine essence—