12.This separation of self-consciousness from the other contents of consciousness also gives rise to the discrimination of subject and objects. This discrimination was prepared for, to be sure, by the characteristic differences among the original contents of consciousness, but is fully carried out only as a consequence of this separation. The concept subject has accordingly as a result of its psychological development three different meanings of different scope, each of which may at different times be the one employed. In its narrowest sense the subject is the interconnection of volitional processes which finds expression in the feeling of the ego. In the next wider sense it includes the real content of these volitional processes together with the feelings and emotions that prepare their way. Finally, in its widest significance it embraces the constant ideational substratum of these subjective processes, that is, the body of the individual as the seat of the common sensations.

In the line of development the widest significance is the oldest, and in actual psychical experience the narrowest is continually giving way to a return of one of the others because it can be fully attained only through conceptual abstraction. This highest form is, then, in reality merely a kind of limits towards which the self-consciousness may approach more or less closely.

12a. This discrimination of subject and objects, or the ego and the outer world as it is commonly expressed by reducing first concept to its original affective substratum and the second together in a general concept -- this discrimination of all the considerations responsible for the dualism [p. 223] which first gained currency in the popular view of things and was then carried over into the philosophical systems. It is on this ground that psychology comes to be set over against the other sciences, in particular the natural sciences, as a science of the subject (§ 1, 3a.) This view could be right only under the conditions that the discrimination of the ego from the outer world were a fact preceding all experience and that the concepts subject and objects could be unequivocally distinguished once for all. But neither of these conditions is fulfilled. Self-consciousness depends on a whole series of psychical processes of which it is the product, not the producer.

Subject and object are, therefore, neither originally nor in later development absolutely different contents of experience, but they are concepts which are due to the reflection resulting from the interrelations of the various components of the absolutely unitary content of our immediate experience.

13. The interconnection of psychical processes which makes up consciousness, necessarily has its deepest spring in the processes of combination which are continually taking place between the elements of the single contents of experience. Such processes are operative in the formation of single psychical compounds and they are what give rise to the simultaneous unity of the state of consciousness present at a given moment and also to the continuity of successive states. These processes of combination are of the most various kinds; each one has its individual coloring, which is never exactly reproduced in any second case. Still, the most general differences are those exhibited by the attention in the passive reception of impressions and the active apperception of the same.

As short names for these differences we use the term association to indicate a process of combination in a passive state of attention, and apperceptive combination to indicate a combination in which the attention is active.