Book IV. Addressed to Vincentius Victor. He first shows, that his hesitation on the subject of the origin of souls was undeservedly blamed, and that he was wrongly compared with cattle, because he had refrained from any rash conclusions on the subject. Then, again, with regard to his own unhesitating statement, that the soul was spirit, not body, he points out how rashly Victor disapproved of this assertion, especially when he was vainly expending his efforts to prove that the soul was corporeal in its own nature, and that the spirit in man was distinct from the soul itself.