Sallust, Bellum Jugurthinum 1
“The race of man complains wrongly about its nature, namely the fact that it is feeble in strength, limited in years and ruled more by chance than virtue. To the contrary, you can realize through contemplation that nothing else is greater or more extraordinary—that human nature lacks only perseverance instead of strength or time.
The leader and ruler of mortal life is the mind. When it proceeds to glory along virtue’s path, it is fully powerful, potent and famous; it does not need fortune since fortune cannot grant or revoke honesty, perseverance, or any other good quality from any man.
But a mind seized by desires is dedicated to laziness and worn by obedience to physical pleasure; accustomed to ruinous temptation for too long, when, thanks to sloth, strength, age and wit have diminished, only then is the weakness of nature at fault. Every man shifts his own responsibility to his circumstances.”
 Falso queritur de natura sua genus humanum, quod inbecilla atque aevi brevis forte potius quam virtute regatur. Nam contra reputando neque maius aliud neque praestabilius invenias magisque naturae industriam hominum quam vim aut tempus deesse. Sed dux atque imperator vitae mortalium animus est. Qui ubi ad gloriam virtutis via grassatur, abunde pollens potensque et clarus est neque fortuna eget, quippe quae probitatem, industriam aliasque artis bonas neque dare neque eripere cuiquam potest. Sin captus pravis cupidinibus ad inertiam et voluptates corporis pessum datus est, perniciosa libidine paulisper usus, ubi per socordiam vires tempus ingenium diffluxere, naturae infirmitas accusatur: suam quisque culpam auctores ad negotia transferunt.