Its universal use is analogous to logic and grammar, since it expresses the form and not the matter of conversation. However, it is to be distinguished from them since it has not only an intellectual relation but also a moral--that is, it defines the movements of the will. And so it accompanies conversation, just as a correctly progressive bass accompanies a melody, and serves in the same way to enhance the effect. The most interesting fact about gesticulation is that as soon as conversation assumes the same _form_ there is a repetition of the same gesture. This is the case, however varied the _matter_, that is to say, the subject-matter, may be. So that I am able to understand quite well the general nature of a conversation--in other words, the mere form and type of it, while looking out of a window--without hearing a word spoken. It is unmistakably evident that the speaker is arguing, advancing his reasons, then modifying them, then urging them, and drawing his conclusion in triumph; or it may be he is relating some wrong that he has suffered, plainly depicting in strong and condemnatory language the stupidity and stubbornness of his opponents; or he is speaking of the splendid plan he has thought out and put in execution, explaining how it became a success, or perhaps failed because fate was unfavourable; or perhaps he is confessing that he was powerless to act in the matter in question; or recounting that he noticed and saw through, in good time, the evil schemes that had been organised against him, and by asserting his rights or using force frustrated them and punished their author; and a hundred other things of a similar kind. But what gesticulation alone really conveys to me is the essential matter--be it of a moral or intellectual nature--of the whole conversation _in abstracto_. That is to say the quintessence, the true substance of the conversation, remains identical whatever has brought about the conversation, and consequently whatever the subject-matter of it may be.