Meditations 5.27

Live with the gods. And he does live with the gods who constantly shows to them that his own soul is satisfied with that which is assigned to him, and that it does all that the daemon wishes, which Zeus hath given to every man for his guardian and guide, a portion of himself. And this is every man's understanding and reason.

Marcus Aurelius, Meditations 5.27, translated by George Long

Walk with the Gods! And he does walk with the Gods, who lets them see his soul invariably satisfied with its lot and carrying out the will of that 'genius,' a particle of himself, which Zeus has given to every man as his captain and guide—and this is none other than each man's intelligence and reason.

Marcus Aurelius, Meditations 5.27, translated by C. R. Haines