This paper discusses an issue related to the action of Leibniz's God on substances. As is generally known, Leibniz's substances spontaneously persist in the preestablished world as “monads without windows” having complete spontaneity and no relationship with any other substance. According to Leibniz, God never does any “interposition” in this world which he created, as such an “interposition” would imply a correction to God's plan, and therefore the imperfectness of his intelligence. On the other hand, Leibniz consistently assumes the continuity of God's actions towards substances. Leibniz's God, so to speak, interposes without interposition. Of course, the notion of God “interposing without interposition” seems contradictory and therefore problematic. Can the idea that God never interposes after creation be compatible with the idea that God is continually interposing since creation? I intend to shed light on this problem using the notions of continual creation and divine concurrence.
A useful place to begin is the controversy between Leibniz and Clarke on God's interposition. Next, by recomposing Leibniz's argument for God's continual actions in Essais de Théodicée, I argue that the actions of Leibniz's God amount to a continual creation operating in a similar way after the initial creation. I then elucidate the modus operandi of God's power in the last stage of creation, and examine whether there is a consistent logic between God's action in creation and God's continual action after creation. Finally, in the light of Leibniz's discussion of the notion divine concurrence in Essais de Théodicée and Causa Dei, I will present an interpretation of the relation between divine concurrence and substances'actions.