Seneca,
Moral letters to Lucilius — Letter 98…
“ Why do we lose heart? That which could be done, can be done, if only we purify our souls and follow Nature; for when one strays away from Nature one is compelled to crave, and fear, and be a slave to the things of chance. We may return to the true path; we may be restored to our proper state; let us therefore be so, in order that we may be able to endure pain, in whatever form it attacks our bodies, and say to Fortune: "You have to deal with a man; seek someone whom you can conquer!" ”
