Tertullian

“ Discussion he has inhibited in this way, by designating admonition as the purpose of dealing with a heretic, and the first one too, because he is not a Christian; in order that he might not, after the manner of a Christian, seem to require correction again and again, and “before two or three witnesses,” [6] seeing that he ought to be corrected, for the very reason that he is not to be disputed with; and in the next place, because a controversy over the Scriptures can, clearly, [7] produce no other effect than help to upset either the stomach or the brain. ”