47. This monster’s cavern, your sacred Majesty, thick laid, as seafaring men do say it is, with hidden lairs, and all the neighbourhood thereof, where the rocks of unbelief echo to the howling of her black dogs, we must pass by with ears in a manner stopped. For it is written: “Hedge thine ears about with thorns;” Ecclus. xxviii. 28. and again: “Beware of dogs, beware of evil workers;” Phil. iii. 2. and yet again: “A man that is an heretic, avoid after the first reproof, knowing that such an one is fallen, and is in sin, being condemned of his own judgment.” Tit. iii. 10, 11. So then, like prudent pilots, let us set the sails of our faith for the course wherein we may pass by most safely, and again follow the coasts of the Scriptures. Virgil, Æn. III. 692 f. (Æneas’ coast-voyage round Sicily).