So familiar an occurrence, well known from the remotest antiquity, from which various consequences have been deduced by philosophers, would not in itself possess sufficient importance to arrest our attention, did it not, for all its insignificant appearance, afford us the opportunity of penetrating the depths of our subject.
We may remark that the same transformation takes place inversely—a state in itself disagreeable may become agreeable. This transmutation is to be found at the root of nearly all the pleasures which we call acquired: a taste or smell at first repugnant may become delightful.
The same thing happens with regard to certain physical exercises connected with touch and the muscular sense. The use of alcoholic drinks, of tobacco, of all sorts of narcotics, would furnish us with abundance of examples. Pleasure is found in certain forms of literature which were at first found revolting; the same thing may be said of painting; and the history of music is one long piece of evidence in favour of this transformation of tastes.
In the first place, we have to note that the hackneyed expression, “transformation” of pleasure into pain, and vice versâ, is inaccurate. Pain cannot be changed into pleasure or pleasure into pain, any more than black can be changed into white. What is meant is that the conditions of existence of the one disappear to give place to the conditions of existence of the other. There is succession, but not transformation; a symptom does not transform itself into its opposite.
This succession, abrupt or gradual, leads us to ask whether there might not be a common basis, a certain identity of nature, between the two antagonistic phenomena. The question thus put may be answered by one of two alternative hypotheses.
1. The admission that the difference is fundamental and irreducible, that pain is as clearly to be distinguished from pleasure as the visual sensation is from the auditory sensation: that these feelings constitute an antinomy—an irreconcilable antagonism. The clearest affirmation of this thesis is found in those writers who make pleasure and pain “sensations” comparable to other sensations, and having their own specific character.
2. The admission that the difference is one of degree, not of nature; that the two contrary manifestations are only two moments of the same process; that they differ from each other only as sound differs from noise, or a very acute sound from a very deep one, both resulting from the same cause—the number of vibrations in any given space of time. I am myself inclined to maintain this second hypothesis.
Let us take as an example a simple case where the process is manifested in its totality. We have a person in a so-called indifferent, neutral, or medium state, that is to say, one which cannot be described as agreeable or painful; the individual is simply alive, that is all. He is sensitive to the perfume of flowers; some are placed in his room—pleasure is the result. At the end of an hour all is changed; the subject is incommoded by the smell of the flowers, and avoids them. Hence we have three successive moments: indifference, pleasure, pain.
But these three moments in consciousness have their correlatives in the modifications of the organism: circulation, respiration, motion, the various phases of nutrition. The first answers to the average vital formula of the individual; the second to an increase in the vital functions, and, according to the usual formula (which we shall examine later on), to an augmentation of energy; the third to a lowering of the vital functions and a diminution of energy. Such are the data of observation and experience. Féré’s researches on the olfactory sensations (to mention no others) have shown that the feelings accompanying them, pleasant or otherwise, show themselves in an augmented or diminished pressure on the dynamometer. In a subject whose dynamometric force is normally 50-55, a disagreeable odour lowers the index to 45, an agreeable one raises it to 65. In another (a hysterical patient) the odour of musk, at first very pleasant, raises the dynamometer from 23 to 46; in three minutes it becomes disagreeable, and the pressure sinks to 19.[[38]] We find, therefore, that the organism is subject to perpetual fluctuations, indicated in the consciousness by agreeable or disagreeable feelings: the two opposites are connected with one and the same cause, the vital functions forming their common basis; and I should be inclined to propound the following hypothesis:—
In most cases, if not in all, two contrary processes are going on simultaneously—one of increase, the other of diminution; what comes into the consciousness is only the result of a difference.