IN HIS SEMINAL essay ‘What Is Enlightenment?’ the great Immanuel Kant wrote that the aim of enlightenment is thinking and choosing for oneself – and, more to the point, thinking fruitfully and choosing wisely. That in turn requires being well informed. But mere information is not sufficient; one’s information must be organised into knowledge. And the knowledge must not be mere knowledge for its own sake, but knowledge which gives rise to insight and understanding.

The enduring symbol of the eighteenth-century Enlightenment is a work which set out to answer this precise need. It was designed to be nothing less than a tool for the education, illumination and, hence, liberation of the human mind. It was the Encyclopédie, ou Dictionnaire raisonné des sciences, des arts et des métiers, edited by Denis Diderot with the assistance of Jean Le Rond d’ Alembert. In this vivid and fascinating book Philipp Blom describes the making of the Encyclopédie and the men responsible for it – chief among them Diderot, but with a star cast besides.

Diderot described the aim of the Encyclopédie in his introduction to it in the-following terms: ‘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 to 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’.

A significant feature of this statement is its assertion that education is the route to the good life: education, not faith in past pieties or submission to present tyrannies. And moreover, Diderot meant education in the sciences and humanities, as they had developed in the centuries since the beginning of the Renaissance – a distinction which d’Alembert, continuing the theme, explicitly characterised in his own Preliminary Discourse as a radical break with the outlook of the Middle Ages. The philosophes who created the Encyclopédie were thus knowing propagandists for a view of the world that was secular, scientific and rational. At the same time they were equally conscious and assertive popularisers of new advances in the natural and social sciences, proudly claiming to be neither less nor more than expositors and publicists for them.

Blom gives the story of the Eruyclopédie and its creators a thorough telling. From the long and rich history of encyclopedias – Diderot’s masterpiece was not the first or the largest, nor in the end the best as encyclopedias go; but it is historically the most important – to a brilliantly evocative picture of eighteenth-century Paris, and from skillful biographies of the principal players to entries from the Encyclopédie used appositely as chapter epigraphs, Blom’s account is full, informative, entertaining, and beautifully written. The Encyclopédie has had more books written about it than it has constituent volumes; but this will rank as one of the best introductions available.

The Enyclopédie met with opposition and controversy even as it was being produced, and its editors faced difficulties – ranging from bankruptcy to the threat of imprisonment and sometimes worse, depending on the mood of the authorities. What afflicted it in its own day has continued since. As a fertile field for controversy among historians, even so clear-cut a programme as the one described by Diderot himself for the Encyclopédie has since been challenged or made subject to competing interpretations. An example is the reading forced on the Encyclopeédie by Car1 Becker in his famous book The Heavenly City of the Eighteenth-Century Philosophers, in which he argues that the Encyclopedists’ thinking is steeped in Christian ideas and assumptions. His view has been conclusively refuted by Peter Gay and others, but one does not have to look far to see how wrong Becker is. A persistent theme of the Encyclopédie’s articles, especially those on method and ‘ enquiry(note the very titles of such entries as ‘Observation’, ‘Hypothesis’, ‘System’), is that the empirical method and rational techniques are central to the discovery and organisation of knowledge, and that these are not just inconsistent with appeals to the authority of Scripture or revelation, but actually controvert them. D’Alembert begins his Preliminary Discourse on the organisation of knowledge by defending empiricism robustly, and accepting the implications of doing so: namely, that the fundamentals of ethics and justice have to be based upon facts about human experience, not derived from metaphysical or theological fancies.

When his work on the Encyclopédie was finished, Diderot looked back on it with bitter disappointment. He had come to think that his labours upon it were futile, that the Encyclopédie itself was bad, and that all the ambitious dreams of his youth were therefore wasted. In the process of the exhausting labours he had expended on it over many years he had lost friends, made enemies, and used up his creative energies, to the extent that although, as Blom tells us, he lived nineteen years after the work’s completion, he never wrote the literary masterwork that he and & his friends thought he was capable of. He died suddenly at lunch one day, characteristically quarrelling with his family, his bureau bulging with manuscripts, his life a greater achievement than he knew.

Philipp Blom’s eloquent account of the Encyclopedie story is not only a tribute to a very worthy project of enlightenment and liberation; it is also a thoroughly good read.