The 18th-century French Encyclopédie is one of the monuments of human intellectual history and the embodiment of the values of the Enlightenment. Philipp Blom describes it as a triumph, both in his subtitle and on the first page of his book, where he uses the word again: "a triumph of free thought, secular principle and private enterprise". Yet the achievement, as his subsequent account shows, was never easy or certain. For those who created the Encyclopédie, and especially for the heroic Denis Diderot, it was a treadmill, an enemy of promise, falling far short of its original aims, carrying the constant threat of prosecution by the authorities of State and Church, and standing in the way of other creative work. When it was completed in 1772, after 25 years of effort, Diderot had no sense of triumph, only of opportunities sacrificed and friendships lost.
To his credit, and our greater delight, Blom tells us as much about the antagonisms and uncertainties along the way as he does about the eventual success of the venture. Diderot was first enrolled by a consortium of booksellers in 1747, to assist the mathematician Jean d'Alembert in producing a French version of Chambers' Cyclopaedia. Subtitled "a reasoned dictionary of sciences, crafts and trades", the Encyclopédie was primarily intended to be utilitarian: the subscriber would be given, in alphabetical order, an account of the present state of scientific and medical knowledge, manufacturing processes, crafts and techniques, all illustrated in the final volumes of plates. The idea was unusual, implying that the work of ordinary craftsmen deserved such close attention, but it was the bits between the sciences, crafts and trades that were to get the Encyclopedists into trouble.
For one thing, the Encyclopédie had a rival, in the form of the Dictionnaire universel, known as the Dictionnaire de Trévoux, which the Jesuits had been publishing, in various revisions, since 1704. The majority of the Encyclopedists were laymen and sceptics whose work was not only a commercial, but also an intellectual challenge to the Jesuits. As the Church had the power of the State behind it - and the penalties for questioning the authority of either of them were savage - the writers of the Encyclopédie had to achieve a nice balancing act. They exercised a lot of ingenuity. The article Arche de Noë, for example, exhaustively describes the dimensions of Noah's Ark and the amount of fodder necessary to sustain the animals inside it for the period of the Flood, without stating in so many words how improbable it was that one man and his wife could construct and load such a vessel: the readers would draw their own conclusions, particularly in the context of the Encyclopédie's other articles on the practicalities of carpentry, shipbuilding and animal husbandry; cross-referencing became one of the Encyclopedists' crafts. And, though Christianity was protected from criticism, the ban did not apply to other faiths, so religion could be attacked through Islam or Judaism (which, as Blom points out, is why the work has been accused of anti-Semitism).
If Diderot is the hero of the Encyclopédie, its unsung workhorse was the little-known Louis de Jaucourt, whose labours remind us that writing any encyclopaedia is a matter of patient research and hard graft. Blom makes oddly conflicting assessments of de Jaucourt's contribution: 14,000 articles at a rate of more than four a day for 10 years; or (50 pages later), 15,039 articles between 1759 and 1765, an average of more than eight a day. Whichever figure you prefer, it is a lot of work; and de Jaucourt was effectively unpaid.
There were, in all, around 150 contributors to the 17 volumes of text. As with any such undertaking, the problems came with the big names. Voltaire, living just beyond the Swiss border, offered a few contributions and some unhelpful interference. Jean-Jacques Rousseau fell out with everyone, a victim of rampant paranoia. Even d'Alembert, whose introductory essay set the agenda for all that followed, caused trouble with an ill-judged article on Geneva which went too far in its praise for republican government, and was sidetracked by other interests. Only Diderot held it all together to the end.
Blom ascribes the ultimate, seemingly improbable survival of the Encyclopédie to economic factors: "the down-to-earth bourgeois calculation that there was simply too much money bound up in the enterprise to allow it to migrate to Holland or Prussia". In this sense, rather than in its materialism, and its republican, anti-clerical opinions, the work was a herald of the coming age and of the industrial revolution that would make obsolete most of the crafts described in its pages; it remains a source of information on pre-industrial life. In many ways it served the same ends as a modern encyclopaedia: to educate and inform. At the same time, though, it was philosophical, provocative and opinionated in ways that few modern works of reference would dare to be, defying rather than reflecting the dominant wisdom of its time.