 One can also arrive at the simplicity doctrine via the divine necessity. As maximally perfect, as that than which no greater can be conceived, God must be a metaphysically necessary being, one that cannot not exist. A necessary being is one whose possibility entails its existence, and whose nonexistence entails its impossibility. But what could be the ground of this necessity of existence if not the identity in God of essence and existence, possibility and actuality? Saying that God exists in all metaphysically possible worlds does not provide a ground, but merely a graphic Leibnizian representation, of the notion of necessary being. The possible worlds representation also does not distinguish the necessity of God from that of an abstract object such as the set of even primes. God is not just another necessary being among necessary beings; he is uniquely necessary as the source and ground of everything distinct from himself, including all non-divine necessary beings. Indeed, God is uniquely unique, i.e., unique in his mode of uniqueness, in that he is not one of a kind, or necessarily one of a kind, but unique in transcending the kind-instance difference altogether. A divine being cannot possess contingent modal status: if God exists, then he is necessary, and if he does not exist, then he is impossible. So if God exists, then there is a very tight connection between the divine nature and the divine existence. The simplicity doctrine in its traditional and strongest form assays this ‘tightness’ as identity. The divine simplicity thus grounds the divine necessity. God is necessary because he is simple. It is easy to see that the divine simplicity also grounds God’s possession of essential properties. God has his attributes essentially because he is identical to his attributes. Nothing is more essential to a thing than something to which it is identical.