Since humility comes from a knowledge of ourselves, pride necessarily springs from ignorance of ourselves. Whoever, therefore, seriously desires to acquire humility must earnestly labor to know himself. How, in fact, can he be otherwise than humbled who, looking into his heart with the light of truth, finds himself filled with sins; defiled with the stains of sinful pleasures; the sport of a thousand errors, fears, and caprices; the victim of innumerable anxieties and petty cares; oppressed by the weight of a mortal body; so forward in evil and so backward in good? Study yourself, then, with serious attention, and you will find in yourself nothing of which to be proud.
--Louis de Granada, The Sinner's Guide