As a bishop he won universal admiration. Councils could do nothing without his presence. Emperors condescended to sue for his advice. He wrote letters to all parts of Christendom. He was alike saint, oracle, prelate, and preacher. He labored day and night, living simply, but without monkish austerity. At table, reading and literary conferences were preferred to secular conversation. His person was accessible. He interested himself in everybody's troubles, and visited the forlorn and miserable. He was indefatigable in reclaiming those who had strayed from the fold. He won every heart by charity, and captivated every mind with his eloquence; so that Hippo, a little African town, was no longer "least among the cities of Judah," since her prelate was consulted from the extremities of the earth, and his influence went forth throughout the crumbling Empire, to heal division and establish the faith of the wavering,--a Father of the Church universal.

Yet it is not as bishop, but as doctor, that he is immortal. It was his mission to head off the dissensions and heresies of his age, and to establish the faith of Paul even among the Germanic barbarians. He is the great theologian of the Church, and his system of divinity not only was the creed of the Middle Ages, but is still an authority in the schools, both Catholic and Protestant.

Beacon Lights of History, Volume IV — Part 120

Let us, then, turn to his services as theologian and philosopher. He wrote over a thousand treatises, and on almost every subject that has interested the human mind; but his labors were chiefly confined to the prevailing and more subtle and dangerous errors of his day. Nor was it by dry dialectics that he refuted these heresies, although the most logical and acute of men, but by his profound insight into the cardinal principles of Christianity, which he discoursed upon with the most extraordinary affluence of thought and language, disdaining all sophistries and speculations. He went to the very core,--a realist of the most exalted type, permeated with the spirit of Plato, yet bowing down to Paul.

Beacon Lights of History, Volume IV — Part 120

We first find him combating the opinions which had originally enthralled him, and which he understood better than any theologian who ever lived.

Beacon Lights of History, Volume IV — Part 120

But I need not repeat what I have already said of the Manicheans,--those arrogant and shallow philosophers who made such high pretension to superior wisdom; men who adored the divinity of mind, and the inherent evil of matter; men who sought to emancipate the soul, which in their view needed no regeneration from all the influences of the body. That this soul, purified by asceticism, might be reunited to the great spirit of the universe from which it had originally emanated, was the hopeless aim and dream of these theosophists,--not the control of passions and appetites, which God commands, but their eradication; not the worship of a Creator who made the heaven and the earth, but a vague worship of the creation itself. They little dreamed that it is not the body (neither good nor evil in itself) which is sinful, but the perverted mind and soul, the wicked imagination of the heart, out of which proceeds that which defileth a man, and which can only be controlled and purified by Divine assistance. Augustine showed that purity was an inward virtue, not the crucifixion of the body; that its passions and appetites are made to be subservient to reason and duty; that the law of temperance is self-restraint; that the soul was not an emanation or evolution from eternal light, but a distinct creation of Almighty God, which He has the power to destroy, as well as the body itself; that nothing in the universe can live without His pleasure; that His intervention is a logical sequence of His moral government. But his most withering denunciation of the Manicheans was directed against their pride of reason, against their darkened understanding, which led them not only to believe a lie, but to glory in it,--the utter perverseness of the mind when in rebellion to divine authority, in view of which it is almost vain to argue, since truth will neither be admitted nor accepted.