On The Holy Trinity by St. Augustine
Chapter 9.--The Same Argument is Continued.
14. For the soul loving its own power, slips onwards from the whole which is common, to a part, which belongs especially to itself. And that apostatizing pride, which is called |the beginning of sin,| whereas it might have been most excellently governed by the laws of God, if it had followed Him as its ruler in the universal creature, by seeking something more than the whole, and struggling to govern this by a law of its own, is thrust on, since nothing is more than the whole, into caring for a part; and thus by lusting after something more, is made less; whence also covetousness is called |the root of all evil.| And it administers that whole, wherein it strives to do something of its own against the laws by which the whole is governed, by its own body, which it possesses only in part; and so being delighted by corporeal forms and motions, because it has not the things themselves within itself, and because it is wrapped up in their images, which it has fixed in the memory, and is foully polluted by fornication of the phantasy, while it refers all its functions to those ends, for which it curiously seeks corporeal and temporal things through the senses of the body, either it affects with swelling arrogance to be more excellent than other souls that are given up to the corporeal senses, or it is plunged into a foul whirlpool of carnal pleasure.