Encyclopédie, ou dictionnaire raisonné des sciences, des arts, et des métiers, par une société de gens de lettres (Encyclopedia, or reasoned dictionary of sciences, arts, and craft by a society of a people of letters)

“Que sais-je?”—“What do I know?” asked the essayist Michel de Montaigne as he tested the world with a compassionate but pressing skepticism. His intellectual descendant, the philosopher Denis Diderot, changed the question as editor of the Encyclopédie, the signal document of the Enlightenment, which asks “Que savons-nous?”—“What do we know?” What do we know about nature, culture, God, ethics, printing, architecture, medicine? The answers—including contributions from Voltaire, Rousseau, Montesquieu, d’Alembert, and others—eventually ran to 28 volumes. Shown here is a foldout chart categorizing human understanding by dividing it under “Memory,” “Reasoning,” and “Imagination.” The Encyclopédie, twice suppressed, represents the supreme collective achievement of the emergent philosophe movement in France.