They soon reached the banks of the Peretola brook, whence the cranes may be seen rising in flocks at daybreak. During the chase, which was abundantly successful, Messer Betto Brunelleschi never ceased pondering the words Guido had used. And by dint of much thinking, he discovered their signification. Hailing Messer Bocca with loud cries, he said to him: "Come hither, Messer Bocca! I have just guessed what it was Messer Guido meant us to understand. He told us we were at home in a graveyard, because the ignorant be for all the world like dead men, who, according to the Epicurean doctrine, have no faculty of thought or knowledge." Messer Bocca replied, shrugging his shoulders, he understood better than most how to fly a Flanders hawk, to make knife-play with his enemies, and to upset a girl, and this was knowledge sufficient for his state in life. Messer Guido continued for several years more to study the science of Love. He embodied his reflexions in canzones, which it is not given to all men to interpret, composing a book of these verses that was borne in triumph through the streets, garlanded with laurel. Then, seeing the purest souls are not without alloy of terrestrial passions, and life bears us one and all along in its sinuous and stormy course, it fell out that at the turning-point of youth and age, Messer Guido was seduced by the ambitions of the flesh and the powers of this world. He wedded, to further his projects of aggrandizement, the daughter of the Lord Farinata degli Uberti, the same who one time reddened the Arbia with the blood of the Florentines. He threw himself into the quarrels of the citizens with all the pride and impetuosity of his nature. And he took for mistresses the Lady Mandetta and the Lady Giovanna, who represented the one the Albigensians, the other the Ghibellines. It was the time when Messer Dante Alighieri was Prior of the Arts and Liberty. The city was divided into two hostile camps, those of the Bianchi and the Neri. One day when the principal citizens were assembled in the Piazza of the Frescobaldi, the Bianchi on one side the square and the Neri on the other, to assist at the obsequies of a noble lady of Florence, the Doctors and the Knights were seated as the custom was, on raised benches, while in front of them the younger men sat on the ground on rush mats. One of the latter standing up to settle his cloak, those who were opposite thought he was for defying them. They started to their feet in turn, and bared their swords. Instantly every one unsheathed, and the kinsmen of the dead lady had all the difficulty in the world to separate the combatants.