affinities between different sensations is that they can be relegated to a fundamental unity; they are all, fundamentally, excitations and sympathetic reactions of the same primordial appetite.
This fundamental unity explains, we think, the other great psychological law of association, which connects the sensations with analogous emotions—a law which plays a very important part in expression. Wundt has shown that there is something exact in the images of vulgar language—a hard necessity, a sweet tenderness, bitter griefs, black cares, a somber destiny. These images, so far from being wholly artificial, have their natural origin in the constitution of our sensibility and in the relation of the sensitive organs to the motor muscles. Our sensitive organs are provided with muscles which have the double purpose of better disposing them to receive favorable excitations and removing harmful agents. The mouth takes a different form and expression accordingly as we are tasting a sweetened liquor or swallowing a bitter draught; in the former case, it seems to dispose itself to attract and receive, in the latter to repel and reject. Darkness, a glaring light, a clear daylight, give by turns a different figure to the physiognomy. By virtue of the association of the emotions with similar sensations and of these with their corporeal expression, agreeable or disagreeable feelings—joy, esteem, fear, grief, spite—are manifested by muscular contractions resembling either the action of pleasing tastes and smells, and of the luster of a tempered light, or of bitterness, poisonous odors, darkness, and blindness. If the expression is the same for the physical sensation and the moral feeling, it is because both have their unity, not only in the same field of consciousness, but also in the same movement of the appetite and the will. Whatever the causes and whatever the objects, we simply desire what augments our activity, and repel what diminishes it.
Reciprocally, the willful expression of an emotion which we do not feel, generates it by generating the sensations connected with it, which in their turn are associated with analogous emotions: the actor who expresses and simulates anger ends by feeling it to a certain extent. Absolute hypocrisy is an ideal; it is never complete with a man, realized in full, it would be a contradiction of the will with itself. In every case, Nature is ignorant of it; sincerity is the first law of Nature as it is the first law of morals. So it is with sympathy. Nature knows no isolation of ideal egoism; it brings together, it confounds, it unites. Like heat and light, it can not give life and sensibility to one point without making them radiate upon the other points. Even within the individual organism, it establishes a society; and he who believes himself one and solitary is already several: the I is already the we. In this way, all the organs, the heart, arteries, nerves, and muscles sympathize with the brain, and tell, each in its own language, of the suffering or enjoyment in which they are participating. In this way, too, the brain sympathizes with the organs, changes their
