noun. 1. with regard to psychology, the observation positing that human actions are, at least partly, the outcome of the employment of volition.2. the general orientation that will and choice are imperative aspects within all human acts. 3. With regard to metaphysics, the orientation which will, instead of mind, spirit, or some other agent, is the premise of reality. The most widely acknowledged philosophy of this type is that of Arthur Schopenhauer, a well-known German thinker.