To understand the rolls played by negativity within Kant’s theory of perception, and especially the various uses of disjunctive judgments in identifying perceptible individuals by discriminating them, and also further important, often neglected subtleties of his theory of perception, this chapter first examines two fundamental aspects of perception, both physiologically and within history of philosophy. This background illuminates unequivocally the superiority of Kant’s analysis of perception, also in view of contemporary theories of knowledge.