For I think that ill fortune is better for men than good.  Fortune always cheats when she seems to smile, with the appearance of happiness, but is always truthful when she shows herself to be inconstant by changing.  The first kind of fortune deceives, the second instructs; the one binds the minds of those who who enjoy goods that cheatingly only seem to be good, the other frees them with the knowledge of the fragility of mortal happiness.  So you can see the one is inconstant, always running hither than thither, uncertain of herself; and the other is steady, well prepared and—with the practice of adversity itself—wise.

Boethius, Philosophiae Consolationis, Book II