Nicene and Post-Nicene Fathers, Vol. IV:
Writings in Connection with the Donatist Controversy.: Chapter 22

Chapter 22.—24.  What if the holy and true Church of Christ were to convince and overcome you, even if we held no documents in support of our cause, or only such as were false, while you had possession of some genuine proofs of delivery of the sacred books? what would then remain for you, except that, if you would, you should show your love of peace, or otherwise should hold your tongues? 1958   For whatever, in that case, you might bring forward in evidence, I should be able to say with the greatest ease and the most perfect truth, that then you are bound to prove as much to the full and catholic unity of the Church already spread abroad and established throughout so many nations, to the end that you should remain within, and that those whom you convict should be expelled.  And if you have endeavored to do this, certainly you have not been able to make good your proof; and being vanquished or enraged, you have separated yourselves, with all the heinous guilt of sacrilege, from the guiltless men who could not condemn on insufficient proof.  But if you have not even endeavored to do this, then with most accursed and unnatural blindness you have cut yourselves off from the wheat of Christ, which grows throughout His whole fields, that is, throughout the whole world, until the end, because you have taken offense at a few tares in Africa.

Footnotes

"Obmutescatis" is the most probable conjecture of Migne or "obtumescatis," which could only mean, "you should swell with confusion."