VII. (34) But these men were husbands of many wives and concubines, not only of such as were citizens, as the sacred scriptures tell us. But Isaac had neither many wives nor any concubine at all, but only his first and wedded wife, who lived with him all his life. (35) Why was this? Because the virtue acquired by teaching, which Abraham pursues, requires many things, both such as are legitimate according to prudence, and such also as are illegitimate according to the exegetical contemplations of preliminary instruction. And there is also a virtue which is made perfect by practice, to which Jacob appears to have been devoted; for exercises consist of many and various dogmas and doctrines, some leading and others following, some leading the way, and others arriving later, and bringing at one time more serious, and at other times lighter labours. (36) But the self-instructed race, of which Isaac was a partaker, the excellent country of the mastery over the passions, has received as its share a nature simple, and unmixed, and unalloyed, standing in no need of either practice or instruction in which there is need of the concubine sciences, and not only of the citizen wives; for when God has showered down from above that most requisite benefit of knowledge, self-taught, and having no need of a preceptor, it would be impossible any longer for a man to live with the slavish and concubine arts, having a desire for bastard doctrines as his children. For the man who has arrived at this honour, is inscribed as the husband of the mistress and princess virtue; and she is called in the Greek language, perseverance, but among the Hebrews her name is Rebekkah. (37) For he who, by reason of the happy constitution of his own nature and by the prolific fertility of his soul, has attained to wisdom without encountering labour or enduring hardship, stands in need of no further improvement; (38) for he has at hand the perfect gifts of God, inspired by means of those most ancient graces, and he wishes and prays that they may remain lasting. In reference to which, it appears to me to be that the Author of all goodness gave him perseverance as his wife, in order that his mercies might endure for ever to the man who had her for his wife.