  For instance, in the Treasury of Higher Knowledge (AKBh  ad I, 1ab), Vasubandhu defines action (karman) as  volition (cetanā) and its ensuing result. However, the  action in fact comprises two distinct types of activity: the volition itself and the intentional act (cetayitvā).  Furthermore, the action itself, conceived as a dual process of  volition and its result, in fact consists of three discrete stages:  bodily, verbal, and mental action, corresponding respectively to the  basis of the action (or how it is realized), its own nature, and the  cause which prompts it. Each of these three stages, although  apparently separate, are in fact the same action viewed from three  different angles. From the perspective of its basis, the action is  grounded in the body, which serves as its instrumental medium. From  the perspective of its nature, an action consists in its verbal  and/or habitual expression. Finally, as far as its motivation is  concerned, an action finds its ultimate cause in the realm of the  mental. Thus conception and verbal expression, represent forms of  activity that manifest an individual's intention to express certain  ideas or engage with a certain object of experience. This  intentionality springs from continuous residual impressions  (vāsanā) resulting from past associations of names with the things they designate. 