In his Trattato di Pittura, written in 1435, Leon Battista Alberti recalls Zeuxis, who, judging his own paintings invaluable, refused to put a price on them. The nobility of art and the artist's interests are thus defended in a work which expressed above all the tendencies of a new generation. But it was also the first manifesto in a propaganda campaign whose fruits were to be fully realized a century later. The artist would finally come to be respected, paid for his pains on an equal basis with the man of letters (until he surpassed the latter), be renowned and assured of meriting his fame. Michelangelo rejoiced in the hardness of marble and bronze because these materials would assure the survival of his works over a long period. When Vasari sent him a copy of his Vite, he thanked him with a sonnet, in which he congratulates Vasari for his work on behalf of artists —and not only contemporary artists, since he also refers to those who, having lived in less fortunate times, had fallen into, or risked falling into, oblivion: Or le memorie altrui già spente, accese…