To Florus 1.97

The Manichaean says that an evil will is inspired by a nature that cannot will good, while a good will is poured in by a nature that cannot will evil. Thus he imposes on the natures of each kind of thing a necessity such that their own wills cannot will the opposite. There is certainly a great gulf between him and us. Let us now see how far you have departed from him. You say that the will is free, but only to do evil; it is not free to cease doing evil unless a necessity of willing good is imposed on it by that nature which, to use your words, “cannot will evil” (Augustine, Against Two Letters of the Pelagians 1.7). You therefore define the human race as doing nothing through free choice except sinning, and as unable to do anything else. By this you declare outright that human nature always desires only one thing, evil, and cannot will the opposite. God's nature, however, cannot will evil; therefore, unless it makes evil human nature share in its own necessity, no good action can exist in human nature. After this, God may see in the secrecy of your heart whether you have little love for Mani. But as far as the kinship of your doctrines shows, you have done absolutely nothing except change the order and establish the same thing he asserted.