Lives of the Stoics: The Art of Living from Zeno to Marcus Aurelius

His job, Cato believed, in a tradition begun by Diogenes, was to serve the public good. Not himself. Not expediency. Not his family. But the nation. That’s what real philosophy was about, whether his skeptical great-grandfather or fame-chasing friend Cicero understood it or not.

That Stoic idea of oikeiosis—that we share something and our interests are naturally connected to those of our fellow humans—was as pressing in the ancient world as it is today.

You can and should be interested in everything, the Stoics taught, because you can and should learn wisdom from everything. The more you experience, the more you learn, and, paradoxically, the more humbled you are by the endless amounts of knowledge that remain in front of you.

According to Diogenes Laërtius, Panaetius was the first Stoic to believe that virtue was not self-sufficient, “claiming that strength, health, and material resources are also needed.”

Kierkegaard would later make the distinction between a genius and an apostle. The genius brings new light and work into the world. The genius is the prophet. The creator. The apostle comes next—a mere man (or woman) who communicates and spreads this message.

What’s interesting is that Antipater thought that most of these ethical questions were pretty straightforward. His formula for virtue was “in choosing continually and unswervingly the things which are according to nature, and rejecting those contrary to nature.”

Aristo had seemed to think that philosophy was for the wise man exclusively, for the individual’s self-actualization. His Stoicism worked well in the classroom, and raised interesting debates, but it would not work in the world. Diogenes saw Stoicism differently. It was a way of thinking—as well as a set of rules—for serving the common good, for se

Posidonius lived, as Seneca would later write, as if the whole world was a temple of the gods.

To the Greeks, each of us had a daimon, an inner genius or guiding purpose that is connected to the universal nature. Those who live by keeping the individual and universal natures in agreement are happy, Zeno said, and those who don’t are not.