Denis Diderot was a French philosopher, writer, and art critic who lived in the 18th century. He is best known for his contributions to the Encyclopedie, a compendium of knowledge that was published between 1751 and 1772. Diderot was also a prominent figure in the Age of Enlightenment, advocating for the advancement of science and reason over superstition and religious dogma. He is remembered as one of the most influential thinkers of his time.