Page:Popular Science Monthly Volume 31.djvu/839

Rh the approach or the removal of advantageous or injurious objects. These tendencies, on account of their advantages, are picked out and magnified by natural selection. We may add, with M. Schneider, that the increase of the general activity, even in the absence of a muscular system, is always manifested as expansion, and the decrease of activity as contraction. Expansion and contraction are at the origin of all the other vital movements, and of course of all the signs of expression.

Now let us consider what states of sensibility would correspond among the rudimentary animals with the different modes of general activity, accompanied by movements of expansion and contraction. We shall then have the two following situations: first, approach of an advantageous object, followed by increase of activity beyond the normal state, with pleasure and the movement of general expansion, which is the sign of it; and, second, on the approach of the injurious object, descent of activity below the normal, pain, and the movement of general contraction. With a step further in evolution, the internal movement of contraction, perfecting itself by natural selection, has brought the living being to a massive movement of transport in space, which will take it away from the object—this is the movement of aversion and flight. The movement of expansion, on the contrary, would have provoked a transportation of the whole body of the living being toward the agreeable object it is the movement of inclination and pursuit. Here are two new signs in the natural language. Add to them the idea of the object that causes the pain or the pleasure, and we shall have conscious repulsion and desire.

These are the primary emotions, with the general movement of the body that expresses them at the first moment. We can say, then, contrary to Mr. Spencer, that, if the intensity of an agreeable feeling is expressed by an exaltation and expansion of motive activity, the intensity of a painful feeling is expressed at once by a contraction and diminution of motive activity. In joy the different organs only reproduce and aid the general movement of expansion; the features dilate, the eyebrows turn upward, the entire physiognomy opens, the voice rises and swells, and the gestures expand in more ample and more numerous movements. We can also say correctly that the lungs dilate, and their play is rendered easier; the cerebral functions are performed with more rapidity and ease; the intelligence is more animated; the sensibility more expansive; the will more kindly. In a word, the expression of joy is a general expression of liberty, and, by that fact, of liberality.

Next, we pass to the immediate expression of pain. At the first moment the depression of activity is manifested by a general depression of the motive force. "The lips are relaxed," says Sir Charles Bell, "the lower jaw drops, the upper eyelid falls and covers half of the pupil, and the eyebrows incline like the mouth." It is true that some other muscles simultaneously become tense, and enter into play,