Augustine of Hippo, Against Two Letters of the Pelagians I.29: Julian Opposes the Faith of His Friends to the Opinions of Catholic Believers. First of All, of Free Will

Chapter 29 [XV.]—Julian Opposes the Faith of His Friends to the Opinions of Catholic Believers. First of All, of Free Will.

Now therefore let us see, for the rest, in what way—after thinking that he might calumniously object against me what I believe, and feign what I do not believe—he himself professes his own faith or that of the Pelagians. “In opposition to these things,” he says, “we daily argue, and we are unwilling to yield our consent to transgressors, because we say that free will is in all by nature, and could not perish by the sin of Adam; which assertion is confirmed by the authority of all Scriptures.” If in any degree it is necessary to say this, you should not say it against the grace of God,—you should not give your consent to transgressors, but you should correct your opinion. But about this, as much as I could, and as far as it seemed to be sufficient, I have argued above.