Meditations by Marcus Aurelius Book 3 Page 12

best wheresoever thou dost find it, enjoy freely.

But if nothing thou shalt find worthy to be preferred to that spirit which is within thee; if nothing better than to subject unto thee thine own lusts and desires, and not to give way to any fancies or imaginations before thou hast duly considered of them, nothing better than to withdraw thyself (to use Socrates his words) from all sensuality, and submit thyself unto the gods, and to have care of all men in general: if thou shalt find that all other things in comparison of this, are but vile, and of little moment; then give not way to any other thing, which being once though but affected and inclined unto, it will no more be in thy power without all distraction as thou oughtest to prefer and to pursue after that good, which is thine own and thy proper good.