Consciousness, then, can testify only to the reality of its own states; no more. It can tell us nothing of their causes. It cannot tell us that man has a brain and nervous system, and can tell us nothing of the connection between mental states and the condition of the bodily organs. The chief factor in conduct (habit) lies outside the region of consciousness altogether. In most cases we act as we have been in the habit of acting, and our present conduct expresses the sum of our previous actions and inclinations. Every action we perform assists the formation of a habit, and with every repetition of a particular action we find its performance easier. Indeed, a very powerful criticism of the trustworthiness of consciousness is found in the fact that the determining causes of conduct lie largely in the region of the unconscious or subconscious, and of this territory consciousness can tell us no more than a ripple on the surface of a river can tell us of its depths.

— Chapman Cohen, Determinism or Free-will