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

What had brought this hardworking man to philosophy in the first place? We’re not sure. Had he known about it from birth, growing up not far from Aristotle? Did one of his wealthy clients hand him a book? As he got older, did he start to want something more out of life? Was it a chance encounter on the street or in the same bookstore as Zeno?

The call to find a deeper meaning in life, to figure out how to live, can come to anyone at any time. Saint Paul received his awakening on the road to Damascus; where Cleanthes’s came from we cannot say. What matters most is whether we respond to the call in the first place—whether we pursue that question until we find its answer, or at least until we find our answer.

However he was prompted, we know that after Cleanthes met Zeno, he became his student and remained so for nineteen years. If he was Zeno’s student until the man’s death in 262 BC, that would mean Cleanthes did not begin his philosophical studies until he was nearly fifty years old. That’s a long, hard life as a water-carrier, a long time to toil in obscurity, before pursuing spiritual and mental greatness.

Perhaps Cleanthes started when he was younger and “graduated” after nineteen years, before moving on to another role inside the burgeoning school that Zeno was building. In any case, he likely got his start in philosophy at a later age than Zeno (who was only four years his elder).

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. Given Cleanthes’s dedication to Zeno, it seems likely that the two were never contemporaries or peers, but always master and student. Zeno, the prophet. Cleanthes, the apostle of Stoicism.

Certainly, Cleanthes was the kind of student who warms a teacher’s heart. The one who sits and listens. Who isn’t afraid of asking “dumb” questions. Who puts in the work. Who never gets discouraged, even if they pick things up slower than other students.

Over the course of nearly twenty years, Cleanthes must have sat at the Stoa Poikilē for thousands of hours, not only listening to debates and discussions, but with a front-row seat as the early principles of Stoicism were established. He was there as Zeno divided the curriculum of Stoicism into three parts: physics, ethics, and logic. He would have heard Zeno riff on the choice Heracles made between living a life dedicated to pleasure or one according to virtue, the passage in Xenophon’s Memorabilia that Zeno had first heard in the bookshop and had been so transformed by. Cleanthes, like a sponge, soaked in all of this, believing the whole while that he had much to learn, clearly, for no one with a large ego can remain a student for two decades.

Because of his age, and his methodical, workmanlike approach to things, Cleanthes was sometimes ridiculed as a slow learner and referred to by other students as “the donkey.” When so insulted, he liked to reply that being likened to an ass didn’t bother him because, like the pack animal, he was strong enough to carry the intellectual load Zeno saddled his students with. Zeno, on the other hand, picked a more generous analogy: Cleanthes was like a hard waxen tablet that, being difficult to write upon, nevertheless retains well what’s recorded on it.

Slowly, Cleanthes began to make a name for himself—though it’s impossible to know when he first began writing and publishing for himself.

Some of the first attention he got was not positive. The satirical poet Timon of Phlius parodied him as a simpleton poring over lines of written text like a general reviewing his soldiers:

Who is this, who like a ram ranges over the ranks of warriors? A masticator of words, the stone of Assos, a sluggish slab.

In fact, Assos was famed for its rock quarries and its hard white stone that was used to fashion ancient coffins. When a satirist takes aim at you and finds only your love of language to criticize, it probably says something positive about your character.

So it was for Cleanthes. Quiet. Sober. Hardworking. One with his philosophy. And his money.