Cleanthes the Stoic Philosopher: Life, Teachings, and Legacy of Zeno’s Devoted Successor
Cleanthes. Theodoor Galle, Public domain, via Wikimedia Commons
Cleanthes of Assos (c. 330 BC – c. 230 BC) stands as one of the central figures in early Stoic philosophy. A devoted student of Zeno of Citium and teacher of Chrysippus, Cleanthes preserved and expanded the Stoic system during its formative years in Athens. Known for his remarkable perseverance, moral integrity, and poetic devotion to the divine order of the cosmos, Cleanthes embodied Stoicism in action. His humble life, deep philosophical faith, and his famous Hymn to Zeus reveal a philosopher who lived his ideals with unwavering conviction.
This article explores the life, philosophy, and legacy of Cleanthes the Stoic, highlighting his contributions to Stoic ethics, physics, and spirituality, as well as his lasting influence on later thinkers and modern interpretations of Stoicism.
Early Life and Background
From Boxer to Philosopher
Cleanthes was born in Assos, a small town in the Troad region of Asia Minor (modern-day Turkey), around 330 BC. Before turning to philosophy, he was reportedly a boxer, a fact that symbolizes his enduring nature and strength of will—qualities that would later define his philosophical character. Despite his humble beginnings and limited financial means, Cleanthes’ passion for knowledge drove him to Athens, the intellectual capital of the ancient world, where he sought out wisdom among its philosophical schools.
Student of Zeno and the Cynics
Upon arriving in Athens, Cleanthes initially studied under Crates of Thebes, a Cynic philosopher known for his emphasis on virtue and simplicity. Soon after, he encountered Zeno of Citium, the founder of Stoicism, and became one of his most devoted pupils. While Zeno taught the principles of living in harmony with nature and using reason to guide life, Cleanthes lived those teachings through his actions, exemplifying the practical side of Stoicism.
Hardship, Perseverance, and Moral Example
The Water-Carrier Philosopher
Cleanthes’ early years as a student were marked by extreme poverty. To support himself while studying under Zeno, he worked at night carrying water and doing manual labor for small wages. Because of this, he was nicknamed Phreantles—“the Well-Water-Collector.” Rather than seeing such labor as degrading, Cleanthes viewed it as a way to practice discipline, humility, and endurance, values central to Stoic virtue.
His dedication impressed the Athenian Areopagus (council), who reportedly offered him financial support after witnessing his industry and virtue. Cleanthes, however, refused the gift at Zeno’s urging, demonstrating his independence and integrity—virtues the Stoics prized above all else.
“The Ass Who Carries Philosophy”
Fellow students sometimes mocked Cleanthes for his slow learning and physical labor, calling him “the ass” for his endurance and strength. Cleanthes took the insult as a compliment, replying that it was true—he carried the load of Zeno’s teachings like a strong and patient beast of burden. This humility and resilience made him a model Stoic long before he became head of the school.
Head of the Stoic School
Successor to Zeno
When Zeno of Citium died around 262 BC, Cleanthes succeeded him as head (scholarch) of the Stoic school in Athens. He led the school for more than 30 years, ensuring the continuity of Stoic philosophy during a crucial period. Under his leadership, Stoicism became more than a theoretical system—it became a lived practice centered on virtue, discipline, and harmony with divine reason (logos).
Teacher of Chrysippus
One of Cleanthes’ greatest achievements was mentoring Chrysippus of Soli, who would later become the third head of the Stoic school and systematize its doctrines. Without Cleanthes’ example and stewardship, Stoicism might not have developed the intellectual depth that Chrysippus later achieved. Cleanthes thus served as the moral and structural bridge between the founder Zeno and the philosopher Chrysippus.
Philosophical Teachings of Cleanthes
Though much of Cleanthes’ writings have been lost, fragments and testimonies from later authors such as Diogenes Laertius, Seneca, and Cicero reveal the core of his thought. His philosophy encompassed the three main branches of Stoic philosophy: ethics, physics, and logic.
Stoic Ethics: Living in Accordance with Nature
Cleanthes refined Zeno’s central ethical idea—the goal of life is to live in harmony with nature. While Zeno defined virtue as living “consistently,” Cleanthes added the crucial phrase “with nature”, emphasizing alignment with the rational and divine order of the cosmos. For him, virtue alone is sufficient for happiness, and all external goods—wealth, pleasure, reputation—are indifferent in the pursuit of moral excellence.
He rejected pleasure as a true good, describing it as contrary to nature and morally empty. The wise person, according to Cleanthes, acts from reason, not passion, and finds contentment in virtue rather than in external circumstances.
Acceptance of Fate and Divine Providence
Cleanthes taught that everything in the universe unfolds according to divine reason (logos). True freedom lies in accepting fate willingly, aligning one’s will with the natural order rather than resisting it. His famous line—later echoed by Seneca—captures this:
“Lead me, Zeus, and you too, Destiny, wherever you have assigned me. I will follow willingly; but if I resist, I shall be dragged.”
This idea of cheerful acceptance of fate became one of the cornerstones of Stoic ethics, inspiring later thinkers such as Epictetus and Marcus Aurelius.
Stoic Physics: A Living Universe
Cleanthes also made significant contributions to Stoic physics, which viewed the cosmos as a living, rational organism. He believed that the divine fire or ether permeates all things, giving them life and coherence. The tension (tonos) that animates the world is both physical and spiritual, representing the rational energy that sustains the universe.
He considered the Sun a visible manifestation of divine reason, a sustaining force that nourishes life. For Cleanthes, to understand nature was to understand God, and to live according to nature was to live in accordance with divine will.
Stoic Theology and the Hymn to Zeus
Cleanthes is perhaps best remembered for his Hymn to Zeus, a poem that beautifully expresses the Stoic vision of divine unity and order. In it, he praises Zeus as the embodiment of universal reason, the guiding force of fate, and the source of all good. The hymn reflects Cleanthes’ deep piety and the spiritual side of Stoicism, blending philosophy with devotion:
“Most glorious of immortals, mighty God,
Invoked by many a name, O sovran King of Nature,
Ever all-powerful, ruling all by law,
Hail! For lawful it is for mortals to call on you.”
This hymn represents one of the most profound religious expressions of Stoic thought and remains a testament to Cleanthes’ belief that philosophy and reverence for the divine are inseparable.
Writings and Lost Works
Ancient sources credit Cleanthes with more than 50 works, though only fragments survive. These included treatises on ethics, physics, and logic, such as On Virtue, On Pleasure, and On the Gods. His writings focused more on moral guidance and religious philosophy than on technical logic, distinguishing him from his successor Chrysippus.
Though his works were lost over time, quotations and summaries preserved by later philosophers ensure that his influence endures. His Hymn to Zeus remains the best-preserved and most celebrated example of Stoic literature.
Character and Personal Virtue
Cleanthes’ personal character embodied the Stoic ideals of discipline, self-control, and humility. Ancient writers admired him for living simply, enduring hardship without complaint, and practicing what he preached. He continued working manual labor even as the head of the Stoic school—a striking example of philosophical consistency.
His moral integrity was legendary. He refused money from kings and patrons, preferring self-sufficiency. His calm acceptance of suffering and his commitment to rational living made him a role model for later Stoics.
Death of Cleanthes
Cleanthes died around 232 BC in Athens. Ancient accounts tell that after developing an ulcer, he fasted for several days on medical advice. When told to resume eating, he refused, saying that since he had already advanced far on the road to death, he would not turn back. This stoic calm in facing death epitomized his philosophy of acceptance and rational endurance.
The Roman Senate later honored his memory with a statue in his hometown of Assos—a rare tribute for a Greek philosopher, reflecting his lasting moral authority.
Legacy and Influence
Bridge Between Zeno and Chrysippus
Cleanthes’ most direct legacy lies in his role as the link between Zeno and Chrysippus, ensuring the survival and continuity of Stoic philosophy. He preserved the spirit of Zeno’s teachings, provided the moral model for Stoic life, and trained the philosopher who would expand and systematize Stoicism for future generations.
Religious and Poetic Stoicism
Through his Hymn to Zeus and theological reflections, Cleanthes gave Stoicism a religious and poetic dimension. He transformed abstract philosophical ideas about the universe into a form of reverent worship of divine reason. This aspect deeply influenced later Stoics, especially Marcus Aurelius, whose Meditations echo Cleanthes’ sense of awe toward the cosmic order.
Moral Example for Later Stoics
Roman Stoics such as Seneca, Epictetus, and Marcus Aurelius all admired the early Stoic masters for their character. Cleanthes’ life of hardship, humility, and virtue became a moral archetype—a demonstration that philosophy is not about wealth or fame but about self-mastery and harmony with nature.
Influence on Modern Stoicism
In modern times, as Stoicism experiences a revival among readers and thinkers seeking practical wisdom, Cleanthes’ story continues to inspire. His steadfastness, humility, and sense of purpose resonate with modern themes of resilience, self-reliance, and mindfulness. His prayer to follow fate willingly has been quoted in countless books, podcasts, and Stoic communities as a guide to inner peace amid uncertainty.
Cleanthes in Literature and Philosophy
Cleanthes also appears as a character in David Hume’s 18th-century Dialogues Concerning Natural Religion, where he represents the rational theist position in debates on the existence of God. Though fictionalized, this inclusion reflects how Cleanthes’ name became associated with reasoned piety and the attempt to reconcile faith and rational philosophy.
His emphasis on divine order influenced early Christian thinkers, who saw in Stoicism a precursor to natural theology—the belief that reason and nature reveal divine wisdom.
The Enduring Relevance of Cleanthes
Today, Cleanthes’ teachings offer timeless lessons for individuals seeking meaning in a turbulent world:
- Live with purpose and discipline, regardless of external hardship.
- Accept fate willingly, aligning your actions with the natural and rational order.
- Find divinity in reason and nature, understanding that the universe operates by law and wisdom.
- Cultivate inner virtue rather than chase external success.
His life reminds us that philosophy is not mere speculation but a way of living in harmony with the universe. Cleanthes turned Stoicism from abstract doctrine into a philosophy of life practiced through daily endurance, simplicity, and gratitude.
Conclusion
Cleanthes of Assos remains one of the most admirable figures in ancient philosophy—a man of action as much as of thought. From his humble beginnings as a water-carrier to his leadership of the Stoic school, he exemplified the power of perseverance and integrity. His devotion to Zeno’s teachings, his poetic expression of divine reason in the Hymn to Zeus, and his calm acceptance of fate all show a life lived in perfect accord with Stoic ideals.
Through his moral example, theological insight, and commitment to virtue, Cleanthes the Stoic philosopher left an indelible mark on the history of thought. More than two millennia later, his life continues to inspire those who seek wisdom, strength, and peace in a world governed by reason and fate.