ESSENCE AND EXISTENCE IN LEIBNIZ'S ONTOLOGY
Lorenzo Peña Synthesis Philosophica 12/2
Zagreb, 1997, ISSN 0352-7875
pp. 415-32.

The several orders of compossibility must be sorted out «before» the divine decision to create this or that universe, since God's decision must be grounded in a sufficient reason, which can only arise from the divine essence itself and the intrinsic qualities of the orders among which He has to make the choice; the greatest perfection of an order of things is mirrored and expressed in every integral component of that order. Consequently, the concept of every real thing does from all eternity contain the unavoidability of its existence before the divine decision. Thus every complete concept of a real thing contains the property of being such that the thing will exist if a created universe exists. Then a thing's existence cannot be external to its concept. There is bound to be more in the concept of something that exists than in that of «something» that does not -- since existence is explained through the quidditative property of being an essence that constitutes an integral part of the most perfect series of things. It is such an essential, quidditative perfection which explains the divine decision, and hence existence. Therefore existence can be deduced from that essential perfection. The essence-as-such, the mere possible, contains something from which existence follows. What Leibniz never manages to explain is what distinguishes existence from that quidditative perfection it unavoidably stems from.