This formal respect is not incompatible with many veiled and secret sarcasms, which were as well understood as they were sharply enjoyed by those who read between the lines. It is not surprising that these sarcasms were constantly unjust and shallow. Even those of us who repudiate theology and all its works for ourselves, may feel a shock at the coarseness and impurity of innuendo which now and then disfigures Diderot's treatment of theological as of some other subjects. For this the attitude of the Church itself was much to blame; coarse, virulent, unspiritual as it was in France in those days. Voltaire, Diderot, Holbach, would have written in a very different spirit, even while maintaining and publishing the same attacks on theological opinion, if the Church of France had possessed such a school of teachers as the Church of England found in the Latitudinarians in the seventeenth century; or such as she finds now in the nineteenth century in those who have imported, partly from the poetry of Wordsworth, partly from the historic references of the Oxford Tracts, an equity, a breadth, an elevation, a pensive grace, that effectually forbid the use of those more brutal weapons of controversy which were the only weapons possible in France a century ago.
We have already said so much of the great and important group of articles on arts and trades, that it is unnecessary to add anything further as to Diderot's particular share in them. He visited all the workshops in Paris; he sent for information and specifications to the most important seats of manufacture in the kingdom; he sometimes summoned workmen from the provinces to describe to him the paper works of Montargis, and the silk works and velvet works of Lyons.[180] Much of Diderot's work, even on great practical subjects, was, no doubt, the reproduction of mere book-knowledge acquired at second-hand. Take, for instance, Agriculture, which was undoubtedly the most important of all subjects for France at that date, as indeed at every other date. There are a dozen pages of practical precepts, for which Diderot was probably indebted to one of the farmers at Grandval. After this, he fills up the article with about twenty pages in which he gives an account of the new system of husbandry, which our English Jethro Tull described to an unbelieving public between 1731 and 1751. Tull's volume was translated into French by Duhamel, with notes and the record of experiments of his own; from this volume Diderot drew the pith of his article. Diderot's only merit in the matter--and it is hardly an inconsiderable one in a world of routine--is that he should have been at the pains to seek the newest lights, and above all that he should have urged the value of fresh experiments in agriculture. Tull was not the safest authority in the world, but it is to be remembered that the shrewd-witted Cobbett thought his ideas on husbandry worth reproducing, seventy years after Diderot had thought them worth compiling into an article.