§3

Sensibility is the receptivity of a subject in virtue of which it is possible for the subject's own representative state to be affected in a definite way by the presence of some object. Intelligence (rationality) is the faculty of a subject in virtue of which it has the power to represent things which cannot by their own quality come before the senses of that subject. The object of sensibility is the sensible; that which contains nothing but what is to be cognised through the intelligence is intelligible. In the schools of the ancients, the former was called a phenomenon and the latter a noumenon. Cognition, in so far as it is subject to the laws of sensibility, is sensitive, and, in so far as it is subject to the laws of intelligence, it is intellectual or rational.

§4

In this way, whatever in cognition is sensitive is dependent upon the special character of the subject in so far as the subject is capable of this or that modification by the presence of objects: these modifications may differ in different cases, according to the variations in the subjects. But whatever cognition is exempt from such subjective conditions relates only to the object. It is thus clear that things which are thought sensitively are representations of things as they appear, while things which are intellectual are representations of things as they are. In a representation of sense there is, first of all, something which you might call the matter, namely, the sensation, and there is also something which may be called the form, the aspect namely of sensible things which arises according as the various things which affect the senses are co-ordinated by a certain natural law of the mind.