There is, however, another tendency of the mind in the treatment of its material, a tendency which shows us in actual operation the activity with which we have now become familiar. When we come to look at any particular case of apperception or association we find that the process must go on from the platform which the mind's attainments have already reached. The passing of the mental states has been likened to a stream which flows on from moment to moment with no breaks. It is so continuous that we can never say: "I will start afresh, forget the past, and be uninfluenced by my history." However we may wish this, we can never do it; for the oncoming current of the stream is just what we speak of as ourselves, and we can not avoid bringing the memories, imaginations, expectations, disappointments, etc., up to the present. So the effect which any new event or experience, happening for the first time, is to have upon us depends upon the way it fits into the current of these onflowing influences. The man I see for the first time may be so neutral to me that I pass him unregarded. But let him return after I have once remarked him, or let him resemble a man whom I know, or let him give me some reason to observe, fear, revere, think of him in any way, then he is a positive factor in my stream. He has been taken up into the flow of my mental life, and he henceforth contributes something to it. For example, a little child, after learning to draw a man's face, with two eyes, the nose and mouth, and one ear on each side, will afterward, when told to draw a profile, still put in two eyes and affix an ear to each side. The drift of mental habit tells on the new result and he can not escape it. He will still put in the two eyes and two ears when he has before him a copy showing only one ear and neither eye. In all such cases the new is said to be Assimilated to the old. The customary figure for man in the child's memory assimilates the materials of the new copy set before him. Now this tendency is universal. The mind must assimilate its new material as much as possible, thus making the old stand for the new. Otherwise there would be no containing the fragmentary details which we should have to remember and handle. Furthermore, it is through this tendency that we go on to form the great classes of objects--such as man, animal, virtue--into which numbers of similar details are put, and which we call General Notions or Concepts. We may understand by Assimilation, therefore, the general tendency of new experiences to be treated by us in the ways which similar material has been treated before, with the result that the mind proceeds from the particular case to the general class.