Of the two books, one was published, and the other never was. The _New Essays_ remained in Leibniz's desk, the _Theodicy_ saw the light. And so, to his own and the succeeding generation, Leibniz was known as the author of the _Theodicy_. The articles in journals form the immediate background to the two books. In 1696 Leibniz heard that a French translation of Locke's _Essay concerning Human Understanding_ was being prepared at Amsterdam. He wrote some polite comments on Locke's great work, and published them. He also sent them to Locke, hoping that Locke would write a reply, and that Leibniz's reflexions and Locke's reply might be appended to the projected French translation. But Locke set Leibniz's comments aside. Leibniz, not to be defeated, set to work upon the _New Essays_, in which the whole substance of Locke's book is systematically discussed in dialogue. The _New Essays_ were written in 1703. But meanwhile a painful dispute had broken out between Leibniz [34] and the disciples of Locke and Newton, in which the English, and perhaps Newton himself, were much to blame, and Leibniz thought it impolitic to publish his book. It was not issued until long after his death, in the middle of the century. The discussion with Locke was a failure: Locke would not play, and the book in which the whole controversy was to be systematized never appeared. The discussion with Bayle, on the other hand, was a model of what a discussion should be. Bayle played up tirelessly, and was never embarrassingly profound; he provided just the sort of objections most useful for drawing forth illuminating expositions; he was as good as a fictitious character in a philosophical dialogue. And the book in which the controversy was systematized duly appeared with great eclat. Here is the history of the controversy. In 1695 Leibniz was forty-nine years old. He had just emerged from a period of close employment under his prince's commands, and he thought fit to try his metaphysical principles upon the polite world and see what would come of it. He therefore published an article in the _Journal des Savants_ under the title: 'New System of Nature and of the Communication of Substances, as well as of the Union between Soul and Body'. In the same year Foucher published an article in the _Journal_ controverting Leibniz; and in the next year Leibniz replied with an 'Explanation'. A second explanation in the same year appeared in Basnage's _Histoire des Ouvrages des Savants_, in answer to reflexions by the editor. M. Pierre Bayle had all these articles before him when he inserted a note on Leibniz's doctrine in his article on 'Rorarius', in the first edition of his _Historical and Critical Dictionary_. The point of connexion between Rorarius and Leibniz was no more than this, that both held views about the souls of beasts.