Note also that the angels, being rational, are endowed with free-will, and, inasmuch as they are created, are liable to change. This in fact is made plain by the devil who, although made good by the Creator, became of his own free-will the inventor of evil, and by the powers who revolted with him Nemesius speaks of this at greater length., that is the demons, and by the other troops of angels who abode in goodness.