By David Warren, The Catholic Thing - A skilled, formally practicing heretic in the past might be an Arian, a Gnostic, a Montanist, or a Docetist, Adoptionist, Nestorian, Monophysite, Monothelitist. . .et cetera. But it is getting wickedly hard to be one of these, with any conviction. The most hardened heretic may put a foot wrong, and expose himself as a heretic from his heresy.