OTHER VICES and perturbances are known to be uniform and simple, but vainglory is multiple, multiform, and varied, accompanying the warrior to all fronts and everywhere beguiling the victor. For in both habit and form, in speech, in labor, in prayer, in solicitude, in knowledge in obedience, in lowliness, and all besides, it tries to wound the soldier of Christ, and like a most pernicious rock obscured beneath undulating waves, it brings unexpected and miserable shipwreck for those sailing by a prosperous gale, while they are neither wary nor watchful.
St. John Cassian, The Institutes, XI, 3.