Gregory the Great

Whence the same apostle again admonishes his disciples, saying, "If any man obey not our word, note that man by this epistle; and have no company with him, that he may be confounded." And straightway he added, "Yet count him not as an enemy, but reprove him as a brother." As if to say, Break ye outward peace with him, but guard in your heart's core internal peace concerning him; that your discord with him may so smite the mind of the sinner that peace depart not from your hearts even though denied to him.