Denis Diderot (October 5, 1713 – July 31, 1784) was a French philosopher, art critic, and writer. He was a prominent persona during the Enlightenment and is best known for serving as co-founder and chief editor of and contributor to the Encyclopédie.
Diderot also contributed to literature, notably with Jacques le fataliste et son maître (Jacques the Fatalist and his Master), which emulated Laurence Sterne in challenging conventions regarding novels and their structure and content, while also examining philosophical ideas about free will. Diderot is also known as the author of the dialogue, Le Neveu de Rameau (Rameaus Nephew), upon which many articles and sermons about consumer desire have been based. His articles included many topics of the Enlightenment.

As a philosopher Diderot speculated on free will and held a completely materialistic view of the universe; he suggested all human behavior is determined by heredity. He therefore warned his fellow philosophers against an overemphasis on mathematics and against the blind optimism that sees in the growth of physical knowledge an automatic social and human progress. He rejected the Idea of Progress. In his opinion, the aim of progressing through technology was doomed to fail. He founded his philosophy on experiment and the study of probabilities. He wrote several articles and supplements concerning gambling, mortality rates, and inoculation against smallpox for the Encyclopédie. There he discreetly but firmly refuted dAlemberts technical errors and personal positions on probability.