I have verified this law in establishing the species of analogy of expression between a hunter and his dog, for example. I found--and this was the sign that Mlle. de Jussat was becoming a little tamer each day--that we began to employ analogous expressions, turns of thought almost the same. I found myself accenting my words as she did hers, and I observed in her gestures which resembled mine. In fine, I became a part of her life, without her perceiving it, so careful was I not to startle this soul just ready to be taken by a word that would cause her to feel her danger. This life of watchful diplomacy, to which I was condemned during nearly two months that these simply intellectual relations lasted, did not pass without almost daily internal struggles. To interest this mind, to invade this imagination little by little, was not all of my programme. I wished to be loved, and I knew that this moral interest was only the beginning of passion. This beginning ought to lead in order not to remain useless to something more than a sentimental intimacy. There is in your “Theory of the Passions,” my dear master, a note which I read so much at that time that I know the text by heart: “A well-prepared study of the lives of professional libertines,” say you, “would throw a definite light upon the problem of the birth of love. But the documents are lacking. These men have nearly all been men of action, and who, in consequence, did not know how to relate. However, some works of a superior psychological interest, the “Memoires” of Casanova, the “Private Life of Marshal de Richelieu,” the chapter of Saint-Simon on Lauzun, authorize us to say that nineteen times out of twenty audacity and physical familiarity are the surest means of creating love. This hypothesis confirms our doctrine on the animal origin of this passion.”