Whereas the Transcendental Aesthetic was concerned with the role of the sensibility, the Transcendental Logic is concerned with the role of the understanding, which Kant defines as the faculty of the mind that deals with concepts. Knowledge, Kant argued, contains two components: intuitions, through which an object is given to us in sensibility, and concepts, through which an object is thought in understanding. In the Transcendental Aesthetic, he attempted to show that the "a priori" forms of intuition were space and time, and that these forms were the conditions of all possible intuition. It should therefore be expected that we should find similar "a priori" concepts in the understanding, and that these pure concepts should be the conditions of all possible thought. The Logic is divided into two parts: the Transcendental Analytic and the Transcendental Dialectic. The Analytic Kant calls a "logic of truth"; in it he aims to discover these pure concepts which are the conditions of all thought, and are thus what makes knowledge possible. The Transcendental Dialectic Kant calls a "logic of illusion"; in it he aims to expose the illusions that we create when we attempt to apply reason beyond the limits of experience.