Man and Sin by Piet Schoonenberg (1964) 2.2 BE

Summary of text [comment] pages 72 and 73

Schoonenberg ‘s claim, that every virtue becomes impossible for man living in sin, is not new. Augustine thought likewise. The Council of Carthage said that grace is necessary for fallen man, so as not to commit sin, in order to will and to be able to do what we realize we must do, and so obey God’s commandments. Nobody is good by himself. Nobody uses his freedom of choice in the right way except through Christ.

The 12th century Council of Sens condemned the assertion that our free choice is, by itself, capable of some good.