We may now inquire why men in all parts of the world, when they feel--whether or not they wish to show this feeling--that they cannot or will not do something, or will not resist something if done by another, shrug their shoulders, at the same time often bending in their elbows, showing the palms of their hands with extended fingers, often throwing their heads a little on one side, raising their eyebrows, and opening their mouths. These states of the mind are either simply passive, or show a determination not to act. None of the above movements are of the least service. The explanation lies, I can not doubt, in the principle of unconscious antithesis. This principle here seems to come into play as clearly as in the case of a dog, who, when feeling savage, puts himself in the proper attitude for attacking and for making himself appear terrible to his enemy; but, as soon as he feels affectionate, throws his whole body into a directly opposite attitude, though this is of no direct use to him. * * * * * Let it be observed how an indignant man who resents and will not submit to some injury holds his head erect, squares his shoulders, and expands his chest. He often clinches his fists, and puts one or both arms in the proper position for attack or defense, with the muscles of his limbs rigid. He frowns--that is, he contracts and lowers his brows--and, being determined, closes his mouth. The actions and attitude of a helpless man are, in every one of these respects, exactly the reverse. BLUSHING. [Expression of the Emotions, page 310.] Blushing is the most peculiar and the most human of all expressions. Monkeys redden from passion, but it would require an overwhelming amount of evidence to make us believe that any animal could blush. The reddening of the face from a blush is due to the relaxation of the muscular coats of the small arteries, by which the capillaries become filled with blood; and this depends on the proper vaso-motor center being affected. No doubt, if there be at the same time much mental agitation, the general circulation will be affected; but it is not due to the action of the heart that the net-work of minute vessels covering the face becomes, under a sense of shame, gorged with blood. We can cause laughing by tickling the skin; weeping or frowning, by a blow; trembling, from a fear of pain, and so forth; but we can not cause a blush, as Dr. Burgess remarks, by any physical means--that is, by any action on the body. It is the mind which must be affected. Blushing is not only involuntary, but the wish to restrain it, by leading to self-attention, actually increases the tendency. * * * * * [Page 312.]