Efficiency is that quality of an action, or relation in motion, which makes for the utmost growth of the self with the utmost accuracy as to the things dealt with by the self.
In all actions of a person, things happen to subject and object, which here are a self and things the self acts on. If the self does not grow by something which it does, the action is inefficient; further, if the self has dealt inaccurately with what it deals with, the self is inefficient likewise.