We cannot prevent the illusions. They will not disappear after we identify them. Understanding is the faculty of rules. Knowledge from principles is that in which I apprehend the particular in the universal through concepts. Principles are synthetic modes of knowledge derived from concepts, understanding can never supply them.
Reason applies itself to understanding, never to experience or objects.
When another judgment is required, in addition to the primary proposition, to reach the conclusion. The three types of syllogism are Categorical, Hypothetical and Disjunctive. Reason in the syllogism does not concern itself with intuitions but with concepts and judgments. Even if pure reason does concern itself with objects, it has no immediate relation to them, but only to the understanding. Therefore, the unity of reason is not the unity of experience.