  When Leibniz speaks of a possible world, he means a set of compossible, finite things that God could have brought into existence if he were not constrained by the goodness that is part of his nature. The actual world, on the other hand, is simply that set of finite things that is instantiated by God, because it is greatest in goodness, reality and perfection. Naturally, the fact that we are here experiencing this world – the actual world – means that there is at least one possible world. So are there others?