[2] This word alone would suffice to make the reader lose all confidence in the account that follows it, and yet it is literally true. Diderot adds nothing either to the events or to the temperaments of the characters he introduces. Mademoiselle de La Chaux´s passion for Gardeil, the monstrous ingratitude of her lover, the details of her meeting with him, of their conversation in Diderot´s presence, who had accompanied her to the house of this ferocious beast. The hopelessness touching this betrayed woman, abandoned by him for which she had sacrificed her sleep, her fortune, her reputation, her health, and even the charms by which she seduced him: all this is of the greatest exactness. As Diderot knew the actors in this drama particularly well, for the facts he had been witness to or the friendship that had entrusted him with them were still recent when he resolved to record them, his imagination had not had the time to alter them by adding or subtracting some circumstance to produce a greater effect. And here again is one of the fairly rare accounts of his life, where he says only what has seen, and has seen only what was. As for the curious particularities that he recorded from Mademoiselle de La Chaux and that he documented in his writing, I will add only a single fact - that he omitted through forgetfulness and that was worthy of being conserved - that this so tender, so passionate, so interesting by her extreme sensibility and by her misfortunes, above all so worthy of a better fate, had also been friends with D´Alembert and the Abbot de Condillac. She was in a position to hear and assess the works of these two philosophers. She had even given the latter, who´s Essay on the Origin of Human Knowledge she had read, the very wise advice of returning to his first thoughts, and, if I may use the expression, to begin at the beginning, i.e., the reject with Hobbes the absurd hypothesis of a distinction between two substances in man. I dare say that this very philosophical view, this sole idea of Mademoiselle de La Chaux suggests more breadth, depth and accuracy in her mind that the whole of Condillac´s metaphysics, in which there is in effect a radical and destructive vice that affects the entire system, and yields more or less vague and uncertain results. One sees that Mademoiselle de La Chaux sensed this; and one regrets that Condillac, more docile to the judicious advice of this enlightened woman with uncommon insight, did not follow the route that she pointed him towards. He would not have scattered so many errors over the one he decided upon, and upon which one can only run astray, as happens daily to those that take him as their guide. See, on this philosopher, the preliminary reflections that serve as an introduction to his article, in the METHODICAL ENCYCLOPEDIA, Dictionary of Ancient and Modern Philosophy, t. II, and what I have again in my Historical and Philosophical Memoires on the life