Darwin makes antithesis a principle of expression. Thus the expression of affection in the dog or cat toward its master cannot, says Darwin, be traced in any wise to serviceability, and we must seek its explanation merely as unconsciously and instinctively assumed as directly contrary to the serviceable hostile expressions. A dog’s expression of anger is, or has been, directly serviceable action, but the expressions of affectionate pleasure seem never to have had such an origin, but to have arisen merely as antithetic to the former, and so establishing the utmost distinctness of impression. To convey most clearly a motion of its friendliness the dog naturally assumes those attitudes which are most diverse from its expression of hostility. Their serviceability as expressions is best attained by being completely antithetical, and the more antithetical the better under natural selection. However, if this be the case, antithesis scarcely deserves, it seems to me, the name of a principle of expression, but it merely denominates the fact that opposite emotions in the struggle for existence tend to exhibit themselves in opposite ways as similar emotions in similar ways; but we need neither antithesis nor similarity as a principle. I believe that serviceability past or present either as direct action or as expression is the prime _impetus_ of what we term the expression of the emotions, and I confess I do not see much force in Darwin’s Chapter on Antithesis. If, however, opposition has a meaning for life, as Darwin seems to imply, then does not the expression come under the law of serviceability? If there is any opposition in expression, I should explain this in general by utility rather than by antithesis _per se_. Thus take the gestures instanced by Darwin (_ibid._, p. 65), of pushing away with the hand when telling one to go away, and of pulling toward when telling one to come; these gestures are, indeed, antithetic, but their explanation does not lie in the fact of the antithesis, but in the fact of the past serviceable habit, by which individuals disliked or liked were repelled or attracted. In the present instance the person motioned to may be far beyond the reach of the arms, but still the gesture may be more than mere useless survival, for it acts as emphasis of the vocal expression, and has its influence there. Darwin for some reason constantly ignores the serviceability of expression as such—not so much as a fact, but as a principle—and hence its relation to natural selection, whereby he involves himself in needless difficulties. If an expression is of use, why should it not arise through natural selection as well as a limb, a wing, or an eye? Like other functions, expression may be incidental or may adapt variations attained originally for other ends, but in the case of the voice, at least, we have an original organ of expression as instrument of intercommunication.