If, Honoratus, a heretic and a man trusting heretics seemed to me one and the same, I should judge it my duty to remain silent both in tongue and pen in this matter. But now, whereas there is a very great difference between these two: forasmuch as he, in my opinion, is an heretic, who, for the sake of some temporal advantage, and chiefly for the sake of his own glory and pre-eminence, either gives birth to, or follows, false and new opinions; but he, who trusts men of this kind, is a man deceived by a certain imagination of truth and piety.
Augustine, On the Profit of Believing.
It seems a simple enough distinction, but it is remarkable how rarely people recognize the difference between someone perversely in error and someone in error because of "a certain imagination of truth and piety"; and this is not only true in theological and religious matters.
