If these conclusions really do follow from Mrs. Macdonald’s newly-discovered data, it would be difficult to over-estimate the value of her work, for the result of it would be nothing less than a revolution in our judgments upon some of the principal characters of the eighteenth century. To make it certain that Diderot was a cad and a cheat, that d’Alembert was a dupe, and Hume a liar—that, surely, were no small achievement. And, even if these conclusions do not follow from Mrs. Macdonald’s data, her work will still be valuable, owing to the data themselves. Her discoveries are important, whatever inferences may be drawn from them; and for this reason her book, ‘which represents,’ as she tells us, ‘twenty years of research,’ will be welcome to all students of that remarkable age.
Mrs. Macdonald’s principal revelations relate to the Memoires of Madame d’Epinay. This work was first printed in 1818, and the concluding quarter of it contains an account of the Rousseau quarrel, the most detailed of all those written from the anti-Rousseau point of view. It has, however, always been doubtful how far the Memoires were to be trusted as accurate records of historical fact. The manuscript disappeared; but it was known that the characters who, in the printed book, appear under the names of real persons, were given pseudonyms in the original document; and many of the minor statements contradicted known events. Had Madame d’Epinay merely intended to write a roman a clef? What seemed, so far as concerned the Rousseau narrative, to put this hypothesis out of court was the fact that the story of the quarrel as it appears in the Memoires is, in its main outlines, substantiated both by Grimm’s references to Rousseau in his Correspondance Litteraire, and by a brief memorandum of Rousseau’s misconduct, drawn up by Diderot for his private use, and not published until many years after Madame d’Epinay’s death. Accordingly most writers on the subject have taken the accuracy of the Memoires for granted; Sainte-Beuve, for instance, prefers the word of Madame d’Epinay to that of Rousseau, when there is a direct conflict of testimony; and Lord Morley, in his well-known biography, uses the Memoires as an authority for many of the incidents which he relates. Mrs. Macdonald’s researches, however, have put an entirely different complexion on the case.