Marcus Tullius Cicero (3 January 106 BC – 7 December 43 BC) was a Stoic Roman philosopher, politician, lawyer, orator, political theorist, consul, and constitutionalist. He came from a wealthy municipal family of the Roman equestrian order, and was one of Rome’s greatest orators and prose stylists.
“It is the peculiar characteristic of the [Stoic] wise man that he does nothing which he could regret, nothing against his will, but does everything honorably, consistently, seriously, and rightly, that he anticipates nothing as if it were bound to happen, is shocked by nothing when it does happen under the impression that its happening is unexpected and strange, refers everything to his own judgment, stands by his own decisions. I can conceive nothing which is happier than this. It is an easy conclusion for the Stoics, since they have perceived the final good to be in agreement with nature and living consistently with nature, which is not only the wise man’s proper function, but also in his power. It necessarily follows that the happy life is in the power of the man who has the final good in his power. So the wise man’s life is always happy.” – Cicero, Tusculan Disputations 5.81–2.