1. By "psychical compound", we mean any composite component of our composite experience which is marked off from the, other contents of this experience by particular characteristics, in such a way that it is apprehended as a relatively independent unity, and is, when necessity demands it, designated by a special name. In developing these names, language has followed the general rule that only classes and the most important species into which phenomena may be grouped, shall have special designations, while the, discrimination of concrete compounds is left to immediate perception. Thus, such expressions as ideas, emotions, volitional acts, etc., designate general classes of psychical compounds, such expressions as visual ideas, joy, anger, hope, etc., special species included in these classes. So far as these designations, which have, arisen from practical experience, are based upon actual distinguishing characteristics, they may be retained by science. But science must give an account of the nature of these characteristics and also of the peculiar contents of each of the chief forms of psychical compounds, in order to give every single an exact meaning. In doing this, we must avoid from the first two presuppositions to which the existence of these names might easily mislead us. The first is the view that a psychical compound [p. 91] is an absolutely independent content of immediate experience. The second is the opinion that certain compounds, for example, ideas, have the nature of things. The truth is that these compounds are only relatively independent units. Just as they are made up of various elements, so they themselves unite to form a complete interconnection, in which relatively simple compounds may continually combine to form more composite ones. Then, again, compounds, like the cyclical elements contained in them, are never things, but processes which change from moment to moment, so that it is only through deliberate abstraction, which is, indeed, indispensable for the investigation in many cases, that they can be thought of as constant at any moment (§ 2, p. 13 sq.).
2. All psychical compounds may be resolved into psychical elements, that is, into pure sensations and simple feelings. The two kinds of elements behave, however, in an essentially different manner, in accordance with the peculiar properties of simple feelings as described in §7. The sensational elements found by such a resolution, always belong to one of the sensational systems already considered.
The affective elements, on the other hand, include not only those which correspond to the pure sensations contained in the compounds, but also those due to the interconnection of the elements into the systems of sensational qualities, accordingly, always remain the same, no matter how great a variety of compounds arises, while the systems of simple affective qualities continually increase. Connected with this increase is another attribute which is thoroughly characteristic for the actual nature of psychical processes. The attributes of psychical compounds are never limited to those of the elements that enter into them, but new attributes, peculiar to the compounds themselves, always arise as a result of the combination of these elements. Thus, a visual idea has not only [p. 92] the attributes of the light-sensations and of the sensations of ocular position and movements contained in it, but also that of the spacial arrangement of the sensations, which these elements in themselves do not have. Again, a volition is not only made up of the ideas and feelings into which its single acts may be resolved, but there result from the combination of these acts, new affective elements which are specifically characteristic of the complex volition. Here, again, the combinations of sensational and affective elements are different. In the first case, on account of the constancy of the sensational systems, no new sensations can arise, but only peculiar forms of their arrangement. These forms are the extensive spacial and temporal manifolds. When, on the other hand, affective elements combine, new simple feelings arise, which unite with those originally present to make intensive affective units of composite character.
3. The classification of psychical compounds is naturally based upon the character of the elements that make them up. Those composed entirely or chiefly of sensations are called ideas, those consisting mainly of affective elements, affective processes. The same limitations hold here as in the case of the corresponding elements.
Although compounds are more the products of immediate discrimination among actual psychical processes than the elements are, still, there is at bottom no pure ideational process and no pure affective process, but in both cases we can only abstract to a certain extent from one or the other component.
As in the case of the two kinds of elements, so here we can neglect the accompanying subjective states when dealing with ideas, but must always presuppose some idea for the affective processes. Still, these ideas may be of very different kinds for the single species and varieties of affective processes.
We distinguish, accordingly, three chief forms of ideas: [p. 93] 1) intensive ideas, 2) spacial ideas, 3) temporal ideas; and three forms of affective processes: 1) intensive affective combinations, 2) emotions, 3) volitions. Temporal ideas constitute a sort of link between the two kinds of processes, for certain feeling play an important part in their formation.
