During the second half of the eighteenth century the dominant influence on all the arts was that form of idealism known as Neoclassicism. In France and Germany the ‘excesses’ of the rococo style had, by the middle of the century, produced a general reaction against exuberance and frivolity. That tendency towards classical restraint and harmony which is an essential part of the French tradition of Corneille and Racine, Poussin and Mansart, reasserted itself decisively under the influence of new ideals—the Enlightenment of the Encyclopaedists—and of the new aesthetic theories centred on Rome and best expounded by the expatriate German, Johann Joachim Winckelmann. Neoclassicism is, however, more than a resurgence of the eternal classic tendency in European art. The essential thing is that neoclassic theory advocated the return to classical principles by way of a strict imitation of antiquity, now made easier by the increase of archaeological knowledge and especially by the discovery of, and excavations at, Herculaneum and Pompeii. Greek art, though still almost entirely unknown in the original, was now given a leading place in theory, and the climate of nineteenth-century opinion that used the fifth century B.C. as a touchstone of all artistic excellence was prepared in the 1750s. It is evident that so much enthusiasm expended on so few available examples of Greek art led to a kind of hyperdulia—an enthusiasm which is in itself far more romantic than classical; and indeed one of the distinguishing characteristics of Neoclassicism is precisely this romantic approach to antiquity, and especially to ruins.