Nicene and Post-Nicene Fathers: Series I/Volume V/Against Two Letters of the Pelagians/Book IV/Chapter 3
Chapter 3 [III.]—The Catholics Praise Nature, Marriage, Law, Free Will, and the Saints, in Such Wise as to Condemn as Well Pelagians as Manicheans.
Let every one who, with a catholic mind, shudders at these impious and damnable doctrines, in this tripartite division, shun the lurking-places and snares of this fivefold error, and be so careful between one and another as in such wise to decline from the Manicheans as not to incline to the Pelagians; and again, so to separate himself from the Pelagians as not to associate himself with the Manicheans; or, if he should already be taken hold of in one or the other bondage, that he should not so pluck himself out of the hands of either as to rush into those of the other. Because they seem to be contrary to one another; since the Manicheans manifest themselves by vituperating these five points, and the Pelagians conceal themselves by praising them. Wherefore he condemns and shuns both, whoever he may be, who according to the rule of the catholic faith so glorifies the Creator in men, that are born of the good creature of flesh and soul (for this the Manichean will not have), as that he yet confesses that on account of the corruption which has passed over into them by the sin of the first man, even infants need a Saviour (for this the Pelagian will not have). He who so distinguishes the evil of shameful concupiscence from the blessing of marriage, as neither, like the Manicheans, to reproach the source of our birth, nor, like the Pelagians, to praise the source of our disorder. He who so maintains the law to have been given holy and just and good through Moses by a holy and just and good God (which Manicheus, in opposition to the apostle, denies), as to say that it both shows forth sin and yet does not take it away, and commands righteousness which yet it does not give (which, again, in opposition to the apostle, Pelagius denies). He who so asserts free will as to say that the evil of both angel and man began, not from I know not what nature always evil, which is no nature, but from the will itself, which overturns Manichean heresy, and nevertheless that even thus the captive will cannot breathe into a wholesome liberty save by God’s grace, which overturns the Pelagian heresy. He who so praises in God the holy men of God, not only after Christ manifested in the flesh and subsequently, but even those of the former times, whom the Manicheans dare to blaspheme, as yet to believe their own confessions concerning themselves, more than the lies of the Pelagians. For the word of the saints is, “If we should say that we have no sin, we deceive ourselves, and the truth is not in us.”
- 1 John i. 8.