Abstract: Leibniz claims that the most satisfying, and correct, account of the ontological status of objects of logic (such as ideas or essences, possibilities, and necessary or eternal truths) is that their being consists in being objects of God's understanding; and that this provides an important argument for the existence of God. In this chapter these claims are examined, found plausible, and defended against charges of circularity.

Keywords: circularity, essence, eternal truths, God, Leibniz, ontological status, possibility,