Saint Laurence Justinian says that nobody knows well what humility is, but he who has received the gift thereof from God; that it is of itself very hard to be known, and that there is nothing in which man deceives himself so much as in the knowing what true humility is.
You think, says he, that it consists in saying, you are a sinner, and a miserable creature. If it consisted in that, nothing in the world would be easier; we should all be humble, for we all speak in that manner, and God grant, we believe what we say, and that our words on the occasion are not mere matter of form.
You think that humility consists also in wearing plain clothes, and in employing yourself in mean and despicable offices; by no means—there may still lurk a great deal of pride at bottom. It may very well happen, that by adopting this mode you wish to distinguish yourself from others, and to pass for a better and more humble man than they, and so all may be but a sort of refined pride. Note that these exterior things, as I shall hereafter shew, contribute much to true humility, when they are made use of as they ought, but, after all, it does not consist therein.
"Many," says Saint Jerome, "embrace the shadow and appearance of humility, but few embrace humility itself." It is very easy to look down upon the ground, to speak in a humble tone, to fetch a sigh or two, now and then, and to own one's self a sinner and a miserable creature at every word; but, if you say any thing to these persons which may hurt their feelings in the least, you will see how far they are from true humility. "Let, therefore," adds Saint Jerome, "all feigned and affected language be dropped; it is patience that shows a man to be truly humble"; it is that which is the touch-stone of humility.
Saint Bernard explains more particularly in what this virtue consists, and gives this definition of it. "Humility," says he, "is a virtue whereby a man, from a true knowledge of himself, becomes vile in his own eyes." Humility consists not therefore in words, nor in the exterior; it consists in the sentiments of the heart, in having a low and mean opinion of ourselves founded on the deep sense we have of our own nothingness; and in desiring to be despised by all the world.
Alonso Rodriguez [SJ]
The Exercise of Perfection and Christian Virtues