 In addition to criticizing the “hypostatization” of the ideas of reason, Kant seeks to expose the “subreptions” involved in the use of the ideas. The term “subreption” refers to a fallacy that specifically involves the surreptitious substitution of different kinds of terms and concepts. Kant usually uses the term to refer to the error of confusing or substituting concepts and principles meant for use in experience (those which properly apply to appearances) with principles of “pure reason.” By this means, a concept or principle which is a condition of our experience (e.g., the principle of apperception) is used in a way that assumes its applications to “objects in general” or things in themselves. Alternatively, a most general, formal, principle that would only hold for things in general is taken, by itself alone, to yield knowledge about appearances. This second kind of criticism found throughout the Dialectic thus pertains to Kant’s efforts to expose the subreptions that ground the illusory metaphysical arguments. Ultimately, Kant will also seek to reveal the very specific formal fallacies that vitiate the metaphysical arguments, to demonstrate that (although they have the appearance of soundness) the positions in each case are implicitly grounded in, or deploy, dialectical uses of terms and concepts, misapplications of principles, and conflations of appearances with things in themselves. What we find in Kant’s criticism of metaphysics, in other words, is a complex account, one grounded in a fairly robust theory of human reason. Accordingly, he identifies reason as the locus of certain principles and propensities, and certain “illusions,” which cooperate with misapplications of concepts and principles to create the errors already exposed in the Transcendental Analytic. Although this variety of aims and complaints certainly complicates Kant’s discussions in the Dialectic, it also makes for a richer and more penetrating criticism of metaphysics.