1. Simple feelings may originate in very many more ways than simple sensations, as was noted in §5. Even such feelings as we never observe except in connection with more or less complex ideational processes, have a simple character (p. 34 sq.). Thus, for example, the feeling of tonal harmony, is just as simple as the feeling connected with a single tone.
Several tonal sensations together are required to produce a harmony, so that it is a compound so far as its sensational contents are concerned, but the affective quality of certain harmonious compound clangs is so different from that of the feelings connected with the single tones, that both classes of feelings are, subjectively, equally irreducible. The only essential difference between the two is that the feelings which correspond to simple sensations can be easily isolated from the interconnections of which they form a part in our experience, by the same method of abstraction which we employed in discovering the simple sensations (p. 38). Those, on the other hand, that are connected with some composite ideational compound, can never be separated from the feelings which enter into the compound as subjective complements of the [p. 75] sensations. Thus, for example, it is impossible to separate the feeling of harmony connected with the chord c e g from the simple feelings connected with each of the single tones c, e, and g . The latter may, indeed, be pushed into the background, for as we shall see later (§9, 3a), they always unite with the feeling of harmony to form a unitary total feeling, but they can never be eliminated.
2. The feeling connected with a simple sensation is commonly known as a sense-feeling, or the affective tone of a sensation. These two expressions are capable of misinterpretation in two opposite senses.
There is a tendency to think that by "sense-feeling" we mean not merely a component of immediate experience that may be isolated through abstraction, but one that really exists by itself. "Affective tone", on the other hand, may be regarded as an affective quality that must inevitably belong to a sensation, just as "color-tone" is a necessary determinant of a color-sensation.
In reality, however, a sense-feeling without a sensation can no more exist than can a feeling of total harmony without tonal sensations. When, as is sometimes the case, the feelings accompanying sensations of pain, of pressure, of hot, and of cold, and muscle-sensations, are called independent sense-feelings, it is due to the confusion of the concepts sensation and feeling (p. 36) which is still prevalent, especially in physiology. As a result of this confusion certain sensations, such as those of touch, are called, "feelings", and in the case of some sensations accompanied by strong feelings, as sensations of pain, the discrimination of the two elements is neglected. In the second place, it would be just as inadmissable to ascribe to a given sensation a definite feeling fixed in quality and intensity. The real truth is that in every case the sensation is only one of the many factors that determine the feeling present at a given moment; besides the sensation, the processes that have [p. 76] gone before and the permanent dispositions -- conditions that we can only partially account for in special cases -- play an essential part. The concept "sense-feeling" or "affective tone" is, accordingly, in the double sense the product of analysis and abstraction: first, we must think of the simple feeling as separated from the concomitant, pure sensation, and secondly, we must pick out from among all the various changing affective elements which are connected with a given sensation under different conditions the one that is most constant and is connected with the sensation after the removal, so far as possible, of the influences, that could disturb or complicate the simple effect of the sensation.
The first of these conditions is comparatively easy to meet, if we keep in mind the psychological meaning of the concepts sensation and feeling.
The second is very difficult, and, especially in the case of the most highly developed sensational systems, the auditory and visual, it is never really possible to remove entirely such indirect influences. We can infer what the pure affective tone of a sensation is, only by means of the same method that has already been used for the abstraction of pure sensations (§ 5, p. 28). Here, too, we may assume that only that affective tone which remains constant when all other conditions change, belongs to the sensation itself. The rule is easily applied to sensation, but only with great difficulty to feelings, because the secondary influences referred to are generally as closely connected with the sensation as is the primary occasion of the affective tone. Thus, for example, the sensation green arouses almost unavoidably the idea of green vegetation, and since there are connected with this idea composite feelings whose character may be entirely independent of the affective tone of the color itself, it is impossible to determine directly whether the feeling observed when a green impression is presented, is a [p. 77] pure affective tone, a feeling aroused by the attending idea, or a combination of both.
2a. This difficulty has led many psychologists to argue against the existence of any pure affective tone whatever. They assert that every sensation arouses some accompanying ideas and that the affective action of the sensation is due in every case to these ideas. But the results of experimental variation of the conditions for light-sensations, tell against this view. If the attendant ideas were the only sources of the feeling, it would necessarily be strongest when the sensational contents of the impression were most like those of the ideas. This is by no means the case. The affective tone of a color is greatest when its grade of saturation reaches a maximum.