As a form of shorthand the three Critiques are known as the First, Second, and Third, respectively.

In the first Critique Kant deals with how we come to understand our world; in the second Critique he deals with practical reason and how we act in our world; and in the third Critique he attempts to show a systematic connection between the first two. So, the first deals with how we think about our sensible world, the second deals with how we act in it, and the third supplies a link between the two in terms of felt judgement. In the first he draws together our inner experience with our necessary perception of an external world. He combines perception and understanding through the application of the productive imagination in such a way as to make judgements possible. He links the First and the Third Critiques by arguing that aesthetic judgments, that is, judgements about what is beautiful or sublime, derive from our determination to impose order on our sensory experience. Thus, aesthetics is just like mathematics: it attempts to find unity in experience.