  Earlier, I noted that Spinoza thinks infinitely many non-substantial objects exist: “From the necessity of the divine nature there must follow infinitely many things in infinitely many ways, i.e., everything which can fall under an infinite intellect” (Ip16). Although Spinoza means more by “infinite” than simply “exhaustive,” he clearly intends “exhaustive” as well. How many objects are there? “As many as there can be together” is Spinoza’s reply. That is, Spinoza endorses a principle of ontological plenitude (POP), according to which the greatest number of compossible non-substantial objects actually exists. Part of Spinoza’s motivation for POP may derive from the PSR itself, since if the actual world were sub-maximal, non-existing but intrinsically possible objects would have no reason for not existing, which would be a brute fact. Perhaps it would also be an undesirable brute fact if (per impossibile) a maximal world with fewer objects than the actual world existed; what would explain God’s realization of a smaller maximal collection when a larger maximal collection is possible (see Ip33s2)? In any case, Spinoza’s POP implies that the number of existing objects is necessarily fixed.