To Florus 3.31

Two or three witnesses are ordinarily believed even in a case involving someone’s life. How much more should two sacred witnesses be believed when God’s honor is at stake: the law contained in Deuteronomy and the history recording the kings’ deeds! God himself prescribed how he wished judgment to be given; judgments delivered according to his law testify how his command should be understood. Is there still doubt that Scripture’s authority cannot establish the transmission of sin?

Surely the positions over which we fight such lengthy battles—what you defend and what we defend—are contrary. They are so opposed and incompatible that you fight by persecution and we by argument, you by fury and we by reason. Both sides therefore agree that these statements differ and conflict: children are punished for their parents’ sins; children are not punished for their parents’ sins. Guilt is natural; guilt is not natural. God’s law commands that parents’ sins be charged to children; God’s law commands that parents’ sins not be charged to children. It is obvious that these mutually hostile opinions and propositions cannot both be true.

The rules of trained argument also show that when two opinions arise about uncertain matters, both can be false, but both cannot be true. This can indeed occur in differing alternatives said to admit a middle position, but not in opposites that have no middle. These matters are familiar to dialecticians; for readers unfamiliar with this discipline, however, let us explain them with an example.