The essayist and philosopher Denis Diderot was one of the originators and interpreters of the Age of Enlightenment. This 18th-century movement was based on the belief that right reason, or rationalism, could find true knowledge and lead mankind to progress and happiness. He was the chief editor of its leading testament, the 'Encyclopedie'.
Diderot was born in Langres, France, on Oct. 5, 1713. He studied in Paris from 1729 to 1732, showing an interest in a wide variety of subjects, including languages, theater, law, literature, philosophy, and mathematics. In his early adult life he turned away from Christianity and embraced rationalism.
In 1745 Diderot was hired by publisher Andre Le Breton to translate an English encyclopedia. When he and his co-editor, mathematician Jean d'Alembert, undertook the task, they created a virtually new work, the 'Encyclopedie'. Published in 28 volumes from 1751 to 1772, it was a literary and philosophic work that was to have profound social and intellectual effects. Its publication was troubled by strong reactions against it by both church and state.
The atheism and materialism apparent in some articles enraged many readers. Some of Diderot's writings foreshadowed the evolutionary theories of Charles Darwin. He also formulated the first modern notion of the cellular structure of matter.
Besides his work on the 'Encyclopedie', Diderot also wrote novels, short stories, and plays in which he frequently criticized society and argued for political revolution. He died in Paris on July 30, 1784, only five years before the outbreak of the French Revolution.
In 1745 the
publisher André Le Breton approached Diderot with a view to bringing
out a French translation of Ephraim Chambers' Cyclopaedia, after two
other translators had withdrawn from the project. Diderot undertook
the task with the distinguished mathematician Jean Le Rond
d'Alembert as coeditor but soon profoundly changed the nature of the
publication, broadening its scope and turning it into an important
organ of radical and revolutionary opinion. He gathered around him a
team of dedicated litterateurs, scientists, and even priests, many
of who, as yet unknown, were to make their mark in later life. All
were fired with a common purpose: to further knowledge and, by so
doing, strike a resounding blow against reactionary forces in church
and state. As a dictionnaire raisonné ("rational dictionary"), the
Encyclopédie was to bring out the essential principles and
applications of every art and science. The underlying philosophy was
rationalism and a qualified faith in the progress of the human mind.
In 1749 Diderot
published the Lettre sur les aveugles (An Essay on Blindness),
remarkable for its proposal to teach the blind to read through the
sense of touch, along lines that Louis Braille was to follow in the
19th century, and for the presentation of the first step in his
evolutionary theory of survival by superior adaptation. This daring
exposition of the doctrine of materialist atheism, with its emphasis
on human dependence on sense impression, led to Diderot’ s arrest
and incarceration in the prison of Vincennes for three months.
Diderot’ s work on the Encyclopédie, however, was not interrupted
for long, and in 1750 he outlined his program for it in a
Prospectus, which d'Alembert expanded into the momentous Discours
préliminaire (1751). The history of the Encyclopédie, from the
publication of the first volume in 1751 to the distribution of the
final volumes of plates in 1772, was checkered, but ultimate success
was never in doubt. Diderot was undaunted by the government's
censorship of the work and by the criticism of conservatives and
reactionaries. A critical moment occurred in 1758, on the
publication of the seventh volume, when d'Alembert resigned on
receiving warning of trouble and after reading Rousseau's attack on
his article "Genève." Another serious blow came when the philosopher
Helvétius' book De l'esprit ("On the Mind"), said to be a summary of
the Encyclopédie, was condemned to be burned by the Parliament of
Paris, and the Encyclopédie itself was formally suppressed.
Untempted by Voltaire's offer to have the publication continued
outside France, Diderot held on in Paris with great tenacity and
published the Encyclopédie's later volumes surreptitiously. He was
deeply wounded, however, by the discovery in 1764 that Le Breton had
secretly removed compromising material from the corrected proof
sheets of about 10 folio volumes. The censored passages, though of
considerable interest, would not have made an appreciable difference
on the impact of the work. To the 17 volumes of text and 11 volumes
of plates (1751-72), Diderot contributed innumerable articles partly
original, partly derived from varied sources, especially on the
history of philosophy ("Eclectisme" ["Eclecticism"]), social theory
("Droit naturel" ["Natural Law"]), aesthetics ("Beau" ["The
Beautiful"]), and the crafts and industries of France. He was
moreover an energetic general director and supervised the
illustrations for 3,000 to 4,000 plates of exceptional quality,
which are still prized by historians today. Philosophical and
scientific works. While editing the Encyclopédie, Diderot managed to
compose most of his own important works as well. In 1751 he
published his Lettre sur les sourds et muets ("Letter on the Deaf
and Dumb"), which studies the function of language and deals with
points of aesthetics, and in 1754 he published the Pensées sur
l'interprétation de la nature ("Thoughts on the Interpretation of
Nature"), an influential short treatise on the new experimental
methods in science. Diderot published few other works in his
lifetime, however. His writings, in manuscript form, were known only
to his friends and the privileged correspondents of the
Correspondance littéraire, a sort of private newspaper edited by
Baron Grimm that was circulated in manuscript form. The posthumous
publication of these manuscripts, among which are several bold and
original works in the sciences, philosophy, and literature, have
made Diderot more highly appreciated in the 20th century than he was
in France during his lifetime.
Among his philosophical works, special mention may be made of L'Entretien entre d'Alembert et Diderot (written 1769, published 1830; "Conversation Between d'Alembert and Diderot"), Le Rêve de d'Alembert (written 1769, published 1830; "D'Alembert's Dream"), and the Eléments de physiologie (1774-80). In these works Diderot developed his materialist philosophy and arrived at startling intuitive insights into biology and chemistry; in speculating on the origins of life without divine intervention, for instance, he foreshadowed the evolutionary theories of Charles Darwin and put forth a strikingly prophetic picture of the cellular structure of matter. Though Diderot's speculations in the field of science are of great interest, it is the dialectical brilliance of their presentation that is exceptional. His ideas, often propounded in the form of paradox, and invariably in dialogue, stem from a sense of life's ambiguities and a profound understanding of the complexities and contradictions inherent in human nature.