The late Middle Ages not merely has a successful middle class—it is in fact a middle-class period. - Arnold Hauser

The Renaissance discovery of nature was an invention of nineteenth-century liberalism which played off the Renaissance delight in nature against the Middle Ages, in order to strike a blow at the romantic philosophy of history. For when Burckhardt says that the ‘discovery of the world and of man’was an achievement of the Renaissance, this thesis is, at the same time, an attack on romantic reaction and an attempt to ward off the propaganda designed to spread the romantic view of medieval culture. The doctrine of the spontaneous naturalism of the Renaissance comes from the same source as the theory that the fight against the spirit of authority and hierarchy, the ideal of freedom of thought and freedom of conscience, the emancipation of the individual and the principle of democracy, are achievements of the fifteenth century. In all this the light of the modern age is contrasted with the darkness of the Middle Ages.

The unity of the Middle Ages as a historical period is quite artificial. In reality they fall into three entirely distinct cultural periods—the natural economy of the early Middle Ages; the courtly chivalry of the high Middle Ages; and the urban bourgeois culture of the late Middle Ages. At any rate, the divisions between these three epochs go deeper than those which mark the beginning and the end of the Middle Ages as a whole.

Early Christian art during the first two or three centuries of its existence was merely a development or even a variant of late Roman art. So great is the similarity between late pagan and early Christian work that the decisive change of style must have occurred between the classical and post-classical, not between the pagan and Christian eras.