The “Transcendental Analytic” has been the study of the nature of understanding, especially its categories and principles. Before turning his attention to the faculty of reason in the “Transcendental Dialectic,” Kant thinks it is necessary to include a couple of addenda.

The first is an extended discussion on the distinction between phenomena and noumena, which requests a distinction between a transcendental concept and an empirical concept. Transcendental concepts refer to objects as they supposedly exist “in themselves,” that is, beyond our experience of them. Empirical concepts are always of objects as they appear, “i.e., to objects of a possible experience” (305). Kant attempts to prove that the categories of the understanding are always only of empirical use. The objects of transcendental concepts are noumena and the objects of empirical concepts are phenomena. Kant writes that “intellectual intuition” would be necessary to perceive objects beyond the way in which they appear to us in sensible intuition. This is not something that the mind can do, though, and so we can never have an experience of an object that is not empirical.

After this, Kant provides an appendix on “The Amphiboly of Concepts of Reflection.” An amphiboly is an ambiguity that results from the way in which words are grammatically constructed.