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

This kind of self-talk was a core practice for Stoics, and it wasn’t always negative. Once Cleanthes overheard a solitary man talking to himself and kindly told him, “You aren’t talking to a bad man.” That is to say that one’s self-talk must be strict, but never abusive. It appears his frugality and work ethic followed along similar lines. He was tough. He was firm. But he hardly relished self-punishment.

The Stoics are underrated for their wit. It was certainly a critical tool for Cleanthes, both in responding to criticism and in disarming those he needed to deliver it to. Speaking to a young man who could not seem to grasp his point, he asked, “Do you see?” Yes, of course, replied the youth. “Why, then,” Cleanthes asked, “don’t I see that you see?” When Cleanthes heard his fellow Stoics complaining about a prominent critic of Stoicism, Arcesilaus, who disagreed with their teachings on the role of duty (kathekon), Cleanthes jumped to his defense, saying that by all accounts Arcesilaus appeared to live a dutiful life. When Arcesilaus heard of Cleanthes’s defense of him, he said, “I’m not easily won by flattery,” to which Cleanthes quipped, “True, but my flattery consists in alleging that your theory is incompatible with your practice.”

Throughout their history, Stoics used this kind of good humor as a way to avoid complaining or blaming and to shine a light on how our everyday actions should be aligned with our words. Plutarch, in his essay How to Tell a Flatterer, tells us that Arcesilaus paid back the respect Cleanthes showed him by banishing a student named Baton from his classroom for composing a put-down rhyme about Cleanthes, and not letting Baton back into his school until he had apologized to its subject. We can imagine that forgiveness came easy to Cleanthes and that he probably read the poem with some delight.

Like his master Zeno, Cleanthes was a man who preferred listening to talking and expected students to do the same. Whereas Zeno said that we were given two ears and one mouth for a reason, Cleanthes preferred to quote from Electra:

Silence, silence, light be thy step.

Indeed, his criticism of the Peripatetics (the followers of Aristotle) was that they were no different from a musical instrument like the lyre, producing beautiful sounds but never able to hear for themselves.

While Cleanthes was a listener and often slow and cautious in his thinking, that doesn’t mean he wasn’t a communicator. More and more, Zeno began to rely on his hardworking apostle, especially as the Stoics suffered attacks from rival schools. However difficult it may have been for this penny pincher to splurge on writing materials, we know that several of the prolific Cleanthes’s fifty-some books articulated and explained the Stoic approach to all sorts of topics. Diogenes lists many of his books, but a few stand out:

On Time

On Zeno’s Natural Philosophy (two volumes)

Interpretations of Heraclitus (four volumes)

On Sensation

On Marriage

On Gratitude

On Friendship

On the Thesis That Virtue Is the Same in a Man and a Woman

On Pleasure

On Personal Traits

It is a tragedy of history that all these books are lost.

From the titles alone, we can tell that this man was no stubborn donkey, that his interests were varied and active, and that he had a mind that loved to challenge itself. When he found a topic he liked, he attacked it with vigor, writing multiple volumes on physics, Heraclitus, impulse control, duty, and logic. Nothing interested Cleanthes more than ethics—this man who refused gifts from kings—so it should not surprise us that roughly half of his known works deal specifically with how we should act in the world.

Curiously, what survive directly from Cleanthes’s writings are largely his poetical fragments.* They are filled with beautiful lines that give us glimpses into his unique combination of determination and acceptance. “Fate guides the man who’s willing,” he writes in one short fragment, “drags the unwilling.”

In another, preserved more than three centuries later by Epictetus (and before that by Seneca):

Lead on God and Destiny,

To that Goal fixed for me long ago.

I will follow and not stumble; even if my will

Is weak I will soldier on.

Cleanthes loved the challenge of poetry, believing that the “fettering rules” of the medium allowed him to reach people in a deep and moving way. He offered the analogy of the way that a trumpet focuses our breath into a brilliant sound. This too would be a metaphorical insight that remains central to Stoicism: that obstacles and limitations—if responded to properly—create opportunities for beauty and excellence.

In one short poem, he gives us a powerful definition of what “good” is and should look like:

If you ask what is the nature of the good, listen: