VII. Are There Limits to Knowledge?

Dualism makes the mistake of transferring the opposition of object and subject, which has meaning only within the perceptual realm, to purely fictitious entities outside this realm. Now the distinct and separate things within the perceptual field remain separated only so long as the perceiver refrains from thinking. For thinking cancels all separation and reveals it as due to purely subjective conditions. The Dualist, therefore, transfers to entities behind the percepts determinations which, by themselves, have no absolute, but only relative, validity. He thus divides the two factors concerned in the process of knowledge, viz., percept and concept, into four: (1) the object in itself; (2) the percept which the subject has of the object; (3) the subject; (4) the concept which relates the percept to the object in itself. The relation between subject and object is “real”; the subject is really (dynamically) influenced by the object. This real process is supposed not to appear in consciousness. But it is said to evoke in the subject a response to the stimulation from the object. The result of this response is said to be the percept. This, at length, is supposed to appear in consciousness. The object is thought to have an objective (independent of the subject) reality, the percept a subjective reality. This subjective reality is said to be referred by the subject to the object. This latter reference is called an ideal one. Dualism thus divides the process of knowledge into two parts. The one part, viz., the production of the perceptual object by the thing-in-itself, he conceives of as taking place outside consciousness, whereas the other, the combination of percept with concept and the letter's reference to the thing-in-itself, takes place, according to him, within consciousness.