Denis Diderot (1713–1784) led the multinational team that produced the Encyclopedia, a work much more radical in its aims than its bland name suggests. Seventeen volumes of text and eleven volumes of illustrative plates were published between 1751 and 1772, despite the efforts of French authorities to censor the work. The volumes covered every branch of human knowledge from the tools of artisans to the finest points of theology. Diderot and his collaborators used the occasion to lay out the principles of the Enlightenment as an intellectual movement and to challenge the authority, in particular, of the Catholic church. The article “Encyclopedia” summarized the goals of the project.

ENCYCLOPEDIA (Philosophy). This word means the interrelation of all knowledge; it is made up of the Greek prefix en, in, and the nouns kyklos, circle, and paideia, instruction, science, knowledge. In truth, the aim of an encyclopedia is to collect all the knowledge scattered over the face of the earth, to present its general outlines and structure to the men with whom we live, and transmit this to those who will come after us, so that the work of the past centuries may be useful to the following centuries, that our children, by becoming more educated, may at the same time become more virtuous and happier, and that we may not die without having deserved well of the human race. . . .

We have seen that our Encyclopedia could only have been the endeavor of a philosophical century; that this age has dawned, and that fame, while raising to immortality the names of those who will perfect man’s knowledge in the future, will perhaps not disdain to remember our own names. . . .

I have said that it could only belong to a philosophical age to attempt an encyclopedia; and I have said this because such a work constantly demands more intellectual daring than is commonly found in ages of pusillanimous [timid] taste. All things must be examined, debated, investigated without exception and without regard for anyone’s feelings. . . . We must ride roughshod over all these ancient puerilities [childish sillinesses], overturn the barriers that reason never erected, give back to the arts and sciences the liberty that is so precious to them. . . . We have for quite some time needed a reasoning age when men would no longer seek the rules in classical authors but in nature.

Source: Margaret C. Jacob, The Enlightenment: A Brief History with Documents (Boston: Bedford/St. Martin’s, 2001), 157–58.

Question to Consider

Why would the Catholic church and the French state find Diderot’s vision for the Encyclopedia so threatening?