We don’t know what the motive-powers are. Some certainly are those we call instincts and their powers are bodily needs, self-preservation and the like. Then there is the social instinct, shown in the craving for communication etc.. Some, I suspect, are needs of the soul – all impersonal love, for instance the love of beauty, truth, righteousness, and the feelings connected with them. These powers have to be discussed and sought after.
For the point I am trying to make here, the motives themselves are irrelevant. The point is this: If we recognize a motive in somebody’s action, may it be ever so obvious to us, don’t make the mistake that is so very common:
Don’t assume the other one knows his own motive.
What you detect might very well be the motive. I am inclined to believe that in many cases it really is. But it is a different question whether the other one is conscious of his motive. The two do not coincide; to have a motive and to be conscious of it are two different things, independent of one another.