1. Feelings, like all psychical phenomenal are never permanent states.
In the psychological analysis of a composite feeling, therefore, we must always think of a momentary affective state as held constant. This is easier the more slowly and continuously the psychical processes occur, so that the word feeling has come to be used mainly for relatively slow processes and for those which in their regular form of occurence never pass beyond a certain medium intensity, such as the feelings of rhythm.
Where, on the other hand, a series of feelings succeeding one another in time unite to an interconnected process which is distinguished from preceding and following processes as an individual whole, and has in general a more intense effect on the subject than a single feeling, we call the unitary succession of feelings an emotion.
This very name indicates that it is not any specific subjective contents of experience which distinguish emotion from feeling, but rather the effect which comes from a special combination of particular affective contents.
In this way it comes that there is no sharp line of demarcation between feeling and emotion. Every feeling of greater intensity passes into an emotion, and the separation between the two depends on a more or less arbitrary abstraction. In the case of feelings that have a certain particular form of occurence [ sic ], that is feelings of rhythm, such an abstraction is strictly speaking impossible. The feeling of rhythm is distinguished at most by the small intensity of its moving effect on the subject, which is what gives "emotion" its name. Still, even this distinction is by no means fixed, and when the feelings produced by rhythmical impressions become somewhat more intense, as is usually the case, especially when the rhythm [p. 170] is connected with sensational contents that arouse the feelings greatly, they become in fact emotions. Feelings of rhythm are for this reason important aids both in music and poetry for portraying emotions and arousing them in the auditor.
The names of different emotions, like those of feelings, do not indicate single processes, but classes in which a large number of single affective processes are grouped on the ground of certain common characteristics.
Emotions such as those of joy, hope, anxiety, care, and anger, are accompanied in any concrete case by peculiar ideational contents, while their affective elements also and even the way in which they occur may vary greatly from time to time. The more composite a, psychical processes is, the more variable will be its single concrete manifestations; a particular emotion, therefore, will be less apt to recur in exactly the same form than will a particular feeling. Every general name fore motions indicates, accordingly, certain typical forms in which related affective processes occur.
Not every interconnected series of affective processes is an emotion or can be classed as such under one of the typical forms discriminated by language. An emotion is a unitary whole which is distinguished from a composite feeling only through the two characteristics that it has a definite temporal course and that it exercises a more intense present and subsequent effect on the interconnection of psychical processes. The first characteristic arises from the fact that an emotion is a process of a higher order as compared with a single feeling, for it always includes a succession of several feelings. The second is closely connected with this first characteristic; it depends on the intensification of the effect produced by a summation of the feelings.
As a result of these characteristics emotions have in the [p. 171] midst of all their variations in form a regularity in the manner of their occurence.
They always begin with a more or less intense inceptive feeling which is immediately characteristic in its quality and direction for the nature of the emotion, and is due either to an idea produced by an external impression (outer emotional stimulation) or to a psychical process arising from associative or apperceptive conditions (inner stimulation). After this inceptive feeling comes an ideational process accompanied by the corresponding feelings.
This process shows characteristic differences in the cases of particular emotions both in the quality of the feelings and in the rapidity of the process. Finally, the emotion closes with a terminal feeling which continues even after the emotion has given place to a quiet affective state, and in which the emotion gradually fades away, unless it passes directly into the inceptive feeling of a new emotion. This last case occurs especially in feelings of the intermittent type (cf. inf. 13).
4. The intensification of the effect which may be observed in the course of an emotion, relates not merely to the psychical contents of the feelings that compose it, but to the physical concomitants as well. For single feelings these accompanying phenomena are limited to very slight changes in the innervation of the heart and respiratory organs, which can be demonstrated only by using exact graphic methods (p. 86 sq). With emotions the case is essentially different. As a result of the summation and alternation of successive affective stimuli there is here not only an intensification of the effect on heart, blood-vessels, and respiration, but the external muscles are always affected in an unmistakable manner. Movements of the oral muscles appear at first (mimetic movements), then movements of the arms and of the whole body (pantomimetic movements). In the case of [p. 172] stronger emotions there may be still more extensive disturbances of innervation, such as trembling, convulsive contractions of the diaphragm and of the facial muscles, and paralytic relaxation of the muscles.