 Among his other criticisms of Kant (see the appendix to the first volume of The World as Will and Representation, entitled, “Criticism of the Kantian Philosophy”), Schopenhauer maintains that Kant’s twelve categories of the human understanding – the various categories through which we logically organize our field of sensations into comprehensible and interrelated individual objects – are reducible to the single category of causality, and that this category, along with the forms of space and time, is sufficient to explain the basic format of all human experience, viz., individual objects dispersed throughout space and time, causally related to one another.