Communicability and Pluralism

Communication involves more than one participant.  Thus, grounding, for Kant, the entailment of the universal communicability in judgments of taste is the concept of the latter as necessarily "pluralistic . . . based on some a priori principle", as he puts it in the 'General Comment' that follows #29 of the Critique of Judgment.  However, a priori Pluralism is a problematic concept for not only his system, but for any.  For, it presupposes the possibility of noumenal differentiation, which is arguably indemonstrable, as, for example, some Medieval thinkers, as well as Schopenhauer, hold.  In other words, the thesis of the existence of a plurality of minds, souls, etc. is the product of sheer speculation, with differentiation a characteristic of phenomena alone, according to such views.  Indeed, Kant's theory that cognitive faculties are identical in distinct corporeal entities tends to support such positions.  So, the thesis of a priori Pluralism grounds his Aesthetic theory inadequately, a weakness which is, perhaps, the source of the problems with his concept of Communicability that have been previously discussed.