Voltaire explains his view of historiography in his article on "History" in Diderot's "Encyclopédie": "One demands of modern historians more details, better ascertained facts, precise dates, more attention to customs, laws, mores, commerce, finance, agriculture, population." Already in 1739 he had written: "My chief object is not political or military history, it is the history of the arts, of commerce, of civilization – in a word, – of the human mind." Voltaire's histories used the values of the Enlightenment to evaluate the past. He helped free historiography from antiquarianism, Eurocentrism, religious intolerance and a concentration on great men, diplomacy, and warfare. Peter Gay says Voltaire wrote "very good history", citing his "scrupulous concern for truths", "careful sifting of evidence", "intelligent selection of what is important", "keen sense of drama", and "grasp of the fact that a whole civilization is a unit of study".