Two phenomena are always seen as central to the Renaissance, particularly in Italy: one is the new interest in classical Latin and Greek associated with humanism; the other the dramatic change that occurred in the visual arts, characterized by Giorgio Vasari in his Vite ('Lives', 1550 and 1568) as a process of rebirth and development to a level unsurpassed even by the ancients. Historians have often supposed that the two were closely related, yet it is not immediately obvious why this should be so. Humanism, after all, was an intellectual movement whose origins lie in the fourteenth century; it was principally concerned with texts which few if any artists would have read, not least because they did not possess adequate knowledge of Latin. By contrast, the revival of the arts began in the late thirteenth century; and Renaissance writers tended to parallel it not so much with humanism as with the birth of vernacular literature, especially given that Cimabue and Giotto were both mentioned in Dante's Divina commedia and Simone Martini featured in two famous sonnets of Petrarch. Nor is there much reason to suppose that the preoccupations of humanists would have had direct bearing on the normal activity of artists: the production of paintings and sculptures on religious themes and the design of traditional types of building, such as churches and palaces.