The first two of a series of seven lectures delivered at the Accademia fiorentina from 1541 to 1548. The lectures were published by the author in form of dialogues, divided in five books, with title "Ragionamenti accademici...sopra alcuni luoghi difficili di Dante," Venezia, n.d., 2d ed. ib. 1567. Only the first two lectures are known in their original form. The first (heretofore unedited) is mainly a treatise on the human eye based on Purg. xxx, 118-123; the second deals with the belief in God after a brief exposition of Par. xxxiv, 64-67. cf. the introduction, and M. Barbi, Della fortuna di Dante nel sec. xvi, Pisa, 1890, p. 216 off.