Before anyone comments that these things don't really matter, that surely we've moved on from these rather infantile boundaries and uncharitable forms of condemnation, take a good look at contemporary theological education (and theological colleges - no names... although it's very tempting...) and its effects on the Church and see for yourself why we are the poorer for not insisting everyone has a good grounding in patristics.
“If heretics no longer horrify us today, as they once did our forefathers, is it certain that it is because there is more charity in our hearts? Or would it not too often be, perhaps, without our daring to say so, because the bone of contention, that is to say, the very substance of our faith, no longer interests us? Men of too familiar and too passive a faith, perhaps for us dogmas are no longer the Mystery on which we live, the Mystery which is to be accomplished in us. Consequently then, heresy no longer shocks us; at least, it no longer convulses us like something trying to tear the soul of our souls away from us.... And that is why we have no trouble in being kind to heretics, and no repugnance in rubbing shoulders with them... It is not always charity, alas, which has grown greater, or which has become more enlightened: it is often faith, the taste for the things of eternity, which has grown less...”Henri de Lubac: Further Paradoxes (Newman Press 1958) and reprinted in Paradoxes of Faith (Ignatius Press 1987)