internal self-activity, namely, all living beings, are partly perceived externally and partly known by inference based on the analogy of our inward consciousness. We can never perceive by external sense either a feeling or a thought or a volition; we can only infer these by external signs interpreted by analogy.
12) But here we come to the fact that overthrows Kant's antithesis, which rests for its validity on a question of fact: so soon as we trace a series of mechanical causes back to a vital cause, whether of plant, animal, or man, then the "unity of our experience" is completed; we are satisfied and do not seek further mechanical causes. We change our ground now and inquire into motives or purposes and search for the ideal end and aim which the self-activity of the living being seeks to attain.
13) A motive is an ideal and not a real. It is the thought of a possible determination opposed to some real determination. Even if we say that a conscious being is always controlled by the strongest motive, we are as far as possible from asserting external necessity or what Kant calls the "natural law of causality." For to be constrained by a motive is to be constrained not by a real but by an ideal, not by a previous event but by a future event, a mere possible event. This ideal or possibility arises in the conscious soul as a product of abstraction and constructive imagination; it is created in place of the remembered reality. In the unconscious soul it arises not by abstraction, but by the simplest form of self-seeking and self-reproduction, using its environment as means of self-reproduction.
14) Kant in this antinomy apparently assumes only one kind of search for causes in experience—that for mechanical causes; elsewhere, as in the Critiques of Judgment and the Practical Reason, he notes with special attention the idea of teleological causes. But here he seems to assume that motives and purposes, the causes which are precisely in accordance with transcendental freedom, are identical with mechanical causes or agencies which are in conflict with transcendental freedom.
