During all this time he continued to wear the long black robe and hood and leathern girdle peculiar to the cenobites of the East, which he had donned at Milan shortly after his baptism when he laid aside the dress of his native Africa. Not only his vesture but also his daily life and practices were the same as those which are the privilege and glory of monks, nuns, and hermits. None surpassed him in austerities and self-denial, as none had surpassed him in philosophic lore at Carthage, and at Milan and Rome. The magnificent effects of his extraordinary gifts, fertile ingenuity, and deep learning and broad mind; the influence of his genius on the thoughts and ideas of his own and succeeding ages, may be best gleaned from a brief survey of his writings. Augustine's early aim was to seek truth. He was perplexed with many doubts; he could not conceive the existence of anything real outside of physical bodies; and nothing around him completely and satisfactorily gave him answer. The Manicheans, who had occupied themselves with questions on the nature of God, the creation of the world, and the origin of evil, seemed to have attained on these points some tangible conclusions. For want of better Augustine defended their doctrines without participating in the excesses which distinguished those sectaries. But he felt himself alienated from them, partly because of the lack of the prestige of great men among them, and because he found Faustus, a Manichean bishop and the Goliath of their forces, ignorant of many simple subjects, and unable to give but vague and shallow responses to the questions that agitated his soul. He afterward had a famous controversy with this Faustus, and wrote against him thirty-three books. The results of Augustine's studies were that he was able to refute their attacks on Holy Scripture which they said had undergone serious changes, and to see the falsehood of their main postulate that good proceeds from a good principle and evil from an evil principle; and also to recognize the futility of their objection that the Christians spoke of a human form in God. Against this sect his principal writings are "On the Manners and Customs of the Catholic Church and those of the Manicheans;" "The Utility of Faith," "The Two Souls," and a book against Adimantes, the disciple of Manes, in which he reconciles the contradictions alleged to exist between the Old and the New Testament. From the Manicheans Augustine turned to the Academicians, who were a philosophical sect, and pretended that it was impossible for man to come to the possession of truth. Augustine had many conferences on this subject with his friends in his retreat at Cassiciacum: and the outcome was two books "On Order," and one on "The Blessed Life." These works discussed the matter thoroughly and left the philosophers no loophole of escape.