Humility & Magnanimity

Aquinas' list of virtues does not altogether tally with Aristotle's, though he works hard to Christianize some of the more pagan characters who figure in Ethics. Aristotle's ideal man is great-souled, that is to say, he is a highly superior being who is very conscious of his own superiority to others. How can this be reconciled with the Christian virtue of humility? By a remarkable piece of intellectual legerdemain, Aquinas makes magnanimity not only compatible with humility but part of the very same virtue. There is a virtue, he says, that is the moderation of ambition, a virtue based on on a just appreciation of one's own gifts and defects. Humility is the aspect that ensures that one's ambitions are based on a just assessment of one's defects, magnanimity is the aspect that ensures that they are based on a just assessment of one's gifts.

Anthony Kenny, Medieval Philosophy, Vol 2., 73.