The Philosophers of the Stoic School

Copyright © Donald Robertson, 2013.  All rights reserved.

[Work in progress, links are still being added and minor corrections made.]

In the third century AD, Diogenes Laertius described an ancient philosophical “succession” that began with Socrates and led through the major figures in the Cynic tradition down to the Stoic school, ending with Chrysippus.  The diagram on this page illustrates his account of this philosophical lineage.  Below are a list of some of the most important figures in the Stoic tradition, including the major Cynic precursors.  I’ve indented less well-known or minor figures.  Links are to pages on Wikipedia but you can also find a Wikipedia navigation menu for Stoicism.  The precise chronological order is difficult to determine in some cases and so I’ve followed a rough chronology, placing the names of historically-related figures together.

The Cynic Succession

• Socrates, c. 469 BC – 399 BC, the pre-eminent Greek philosopher.  He introduced the application of dialectic to ethical questions, especially the definition of the cardinal virtues, and the philosophical way of life.  There’s some evidence that certain Stoics considered themselves to be ultimately followers of Socrates.  Likewise, Epictetus mentions him twice as often as Zeno, the founder of the Stoa.
• Antisthenes, 445 – 365 BC, the friend and student of Socrates, who founded a small sect after his death, and (perhaps doubtfully) was claimed to have been the ultimate founder of the Cynic school.
• Diogenes of Sinope, 412/404 – 323 BC, founder of the Cynic philosophical tradition; he probably never met Antisthenes, although he may have been inspired by his writings.
• Crates of Thebes, 365 – 285 BC, Diogenes’ most famous follower, and the most important teacher of Zeno of Citium.
• Zeno of Citium, c. 334 BC – c. 262 BC, began his philosophical career as a follower of Crates, and clearly adopted the Cynic lifestyle, apparently for twenty years, before founding his own school, the Stoa.

Diogenes Laertius claims that the Stoics were part of a wider Ionian philosophical tradition, stretching back to the pre-Socratic philosophers Thales and Anaximander.  They were clearly influenced by Heraclitus, who stands in this tradition, although, curiously, Diogenes Laertius does not mention him as a major precursor of Stoicism for some reason.  Zeno reputedly wrote a book entitled On Pythagoreanism and the influence of many Neopythagorean ideas can be seen in the works of Epictetus and Seneca, in the Roman Imperial period.  However, the most important precursor of Stoicism was probably Socrates.  We’re told it was the desire to emulate his example, which he read about in Xenophon’s Memorabilia, that inspired Zeno to begin studying philosophy.  Zeno then spent twenty years studying philosophy at Athens, attaching himself to three major Socratic sects:

• The Cynics, whose philosophy was his first and most important influence, after he became a follower of Crates of Thebes.
• The Megarian school, who specialised in logic and dialectic, but held a moral philosophy similar in some ways to the Cynics; Zeno studied under Stilpo the head of the school, probably the most popular philosophical teacher of his day, but also under members of the “Dialectician” sect associated with this school, particularly Diodorus Cronus.
• The Academy of Plato, where Zeno studied under the scholarchs Xenocrates and later his successor Polemo; Xenocrates had been a student of Plato, the founder of the school.

Athens at this time was full of thinkers influenced by Socrates.  Zeno was steeped in this Socratic atmosphere.  He was exposed to the teachings of Socrates through these three major schools, which Diogenes Laertius places in a lineage going back to the immediate circle of students surrounding Socrates.  The Cynic succession, he claims, was founded by Antisthenes, whereas the Megarian school being founded by Euclid and the Academy by Plato, that would mean these schools derive from three associates of Socrates himself.  The suggestion may be that different schools developed different aspects of Socrates’ original teaching, which were later re-united by the Stoic school.

A fourth Socratic influence was Xenophon, another friend of Socrates.  Although his small school had ceased to exist by this time, Zeno was inspired by his writings portraying Socrates as a pre-eminent sage.  It should also be noted that the Stoics appear to show more interest in poetry and drama than the other philosophical schools.  They frequently quote Homer and Euripides in particular, and such writings clearly had some influence on them, perhaps mainly in providing examples of tragic figures who they would see as pathologically attached to wealth or reputation, although also sometimes they were a source of positive sayings and examples.  Incidentally, a well-known tradition held that some of Euripides’ plays were co-authored by Socrates so the obvious interest of the Stoics in them could perhaps be more evidence of their dedication to the Socratic tradition.

The Early Stoa (Athens)

Zeno of Citium, c. 334 BC – c. 262 BC, was the founder of the Stoa, as we’ve seen.  These are some of his most notable followers, including several who appear to have broken away from the Stoic school, to some extent.

• Aristo of Chios, c. 320 – 250 BC, the most important “heterodox” Stoic mentioned by Diogenes Laertius, was an associate of Zeno who insisted on an ethical philosophy resembling Cynicism, and rejected the importance of studying logic and physics.
• Herillus of Carthage, fl. 260 BC, an important “heterodox” Stoic mentioned by Diogenes Laertius, apparently a student of Zeno, who became critical of him, he defined the goal of life as knowledge and everything between virtue and vice as “indifferent”.
• Dionysius of Heraclea, dubbed “the Renegade”, 330 – 250 BC, another important “heterodox” Stoic mentioned by Diogenes Laertius, who abandoned Stoicism in favour of the Cyrenaic school, who viewed pleasure as the chief good in life.
• Aratus, 315/310 – 340 BC, an ancient poet-philosopher who apparently studied with Zeno, his Stoic-influenced didactic poem on natural philosophy  Phaenomena survives and was quoted by St. Paul in Acts of the Apostles, speaking to an audience of Epicurean and Stoic philosophers in Greece.
• Persaeus of Citium, 307/306 – 243 BC, a favoured student of Zeno, who was sent in his place to become court advisor to King Antigonus II Gonatas of Macedonia.
• King Antigonus II Gonatas, ruler of Macedonia, who was interested in philosophy, particularly Cynicism, reputedly attended the lectures of Zeno, and was later had his student Persaeus as a court advisor.  He appears to have greatly admired Zeno, although it’s not clear if he considered himself a Stoic.

Cleanthes of Assos, c. 330 BC – c. 230 BC, was the second scholarch.  He was not renowned as a great intellectual.  Passages from his Hymn to Zeus have survived, and these perhaps suggest an emphasis on fatalism and piety.

• Sphaerus of Borysthenes, c. 285 BC – c. 210 BC, was an important student of both Zeno and Cleanthes.

Chrysippus of Soli, c. 279 BC – c. 206 BC, was the third scholarch.  He was typically contrasted with Cleanthes because he was renowned as one of the greatest intellectuals of the ancient world.  He reputedly wrote over 700 books and was greatly preoccupied with the theoretical development of Stoicism.

The Middle Stoa (Roman Republic)

During this transitional and politically-chaotic period, the scholarch Panaetius travelled to Rome to lecture and Stoicism started to become increasingly popular outside of Greece, particularly among important statesman and cultural figures in the Roman Republic.  At the same time, key Stoics began to assimilate elements of Platonic and Aristotelian philosophy, which may have contributed to the eventual disappearance of the formal institution of the Stoa and the dispersal of its remaining students and teachers.

Zeno of Tarsus, fl. 200 BC, was the fourth scholarch.

Diogenes of Babylon, c. 230-150/140 BC, the fifth scholarch, visited Rome as part of an important ambassadorial delegation, along with the Academic Skeptic Carneades and the Aristotelian Critolaus.

• Apollodorus of Seleucia, fl. 150 BC, an important student of Diogenes of Babylon, who may have been influential in promoting the Cynic-Stoic succession reported by Diogenes Laertius (see above).
• Crates of Mallus, fl. 2nd century BC, Stoic natural philosopher who created the first known globe of the Earth.

Antipater of Tarsus, d. 130/129 BC, was the sixth scholarch.

Panaetius of Rhodes, c. 185 – c. 110/09 BC, was the seventh and perhaps the last scholarch of the Athenian Stoa, after his death the formal institution of the Stoa apparently fragmented, and eventually disappeared.

• Mnesarchus of Athens, c. 160 – c. 85 BC, was a student of Antipater of Tarsus, who was apparently one of the leaders of the residual Stoic school at Athens after the death of Panaetius.
• Hecato of Rhodes, fl. 100 BC, an important Stoic philosopher and student of Panaetius.
• Gaius Laelius Sapiens, b. c. 188 BC, called “the Wise”, Roman statesman who studied Stoic philosophy, close friend of Scipio the Younger; Cicero wrote a dialogue in his name about Stoic view on friendship.
• Scipio the Younger, Scipio Aemilianus Africanus, 185 – 129 BC, influential Roman statesman and general, who led the final destruction of Carthage; he formed a circle of friends interested in philosophy, including Stoicism, who were called the “Scipionic Circle”, and included the Stoic philosopher Panaetius

Posidionius of Rhodes, c. 135 BCE – 51 BC, was Panaetius’ most famous student, and may have led a Stoic school relocated to Rhodes, although he may eventually have abandoned Stoicism altogether.

In 87 BC, during the period when Posidonius apparently led the Stoa, the Roman dictator Sulla sacked Athens and most of the formal philosophical schools closed down, perhaps fleeing to preserve their precious founding texts, transporting them to the safety of other locations.

A couple of years after the death of Posidonius, from 49-45 BC the Great Roman Civil War took place, in which the tyrant Julius Caesar overthrew the Roman Republic and established himself as dictator.  Cato (a Stoic) and Cicero (an Academic) were major political opponents of Caesar.  Cato ended up leading the remnants of the Republican army in their last stand against Caesar at Utica in North Africa.  Seneca’s nephew, the Stoic poet Lucan would later describe the events of the Civil War in his epic poem Pharsalia, which (paradoxically) portrays Cato the Younger as the real (moral) victor, though defeated by Caesar, and as the supreme Stoic hero of the Roman world.

• Marcus Tullius Cicero, 106 BC – 43 BC, Roman statesman and philosopher, not a Stoic but an Academic who was greatly influenced by Stoicism and one of our main sources for discussion of Stoic ideas, friend and rival of Cato; he was particularly influenced by the more eclectic Stoicism of Panaetius.
• Cato the Younger, 95 – 46 BC, Roman statesman, philosopher, and military leader, who gave his life at the end of the Civil War in defiance of Julius Caesar, did not write or teach but Cicero calls him the “complete Stoic”, and he was revered by subsequent generations as a Stoic hero.
• Antipater of Tyre, d. c. 45 BC, Stoic philosopher and friend of Cato the Younger, who introduced him to Stoic philosophy.
• Athenodorus Cordylion, of Tarsus, fl. 1st century BC, Stoic philosopher and keeper of the library at Pergamon, where he allegedly expunged passages from Zeno’s texts, seemingly those alluding to the more controversial aspects of Cynicism; he was persuaded by Cato to become his resident philosopher and relocated to Rome.

A series of civil wars followed during the post-Republic period and the Roman Empire was eventually founded when Octavian was made the first Roman emperor, and named Augustus, in 27 BC.  The Roman Imperial period therefore follows.

The Late Stoa (Roman Empire)

By the Roman Imperial period, the formal institution of the Stoa appears to have come to an end, but Stoic lecturers still exist for at least another two centuries, and Marcus Aurelius is the last famous Stoic we know about.  Three of the most important Stoics of this period can be seen as aligned to the same branch of Stoicism: Musonius Rufus, Epictetus, and Marcus Aurelius.  During this period, Stoicism lacked an orthodox centre of teaching and became somewhat fragmented, although there also seems to have been some desire to return to the orthodox teachings of the schools founders, through close study of the texts of Chrysippus in particular.

• Arius Didymus of Alexandria , fl. 1st century BC, Stoic teacher of the Emperor Augustus, the first Emperor and founder of the Roman Empire.
• Horace, 65 – 8 BC, the leading Roman lyric poet during the reign of Augustus, was influenced by Epicureanism but increasingly by Stoicism in his later writings.
• Quintus Sextius, fl. 50 BC, Roman philosopher who combined Stoicism and Neopythagoreanism, much admired by Seneca, who studied with his follower Sotion.
• Athenodorus Cananites, c. 74 BC – 7 AD, Stoic philosopher, student of Posidonius.
• Attalus, fl. 25 AD, Stoic philosopher and teacher of Seneca, whom he much admired and frequently quotes.
• Sotion, fl. 1st century AD, philosopher who combined Neopythagoreanism and Stoicism, a teacher in the school of Quintus Sextius, who taught Seneca.

Seneca the Younger, c. 4 BC – AD 65, was not a Stoic teacher but probably the focus of a small informal circle of Stoic friends, and tutor to the Emperor Nero

• Lucan, 39 – 65 AD, the nephew of Seneca, a Stoic-influenced poet, and author of the Pharsalia, which portrays Cato as a Stoic sage
• Persius, 34 – 62 AD, a Stoic poet, and friend of Lucan, several of whose Stoic-influenced Satires survive
• Cornutus, fl. 60 AD, a Stoic philosopher and teacher, his Compendium of Greek Theology survives.

Euphrates, c. 35 – 118 AD, Stoic philosopher, there are several conflicting claims about his place of birth.  Pliny the Younger met him in Syria.

Musonius Rufus, c. 20/30 AD – 79/101 AD, was the pre-eminent Stoic teacher of the Roman Imperial period, the head of an important school, but not an official scholarch of the Stoa.

Epictetus, AD 55 – 135, was Musonius’ most influential student, and began lecturing at his own Stoic school during the same period as his teacher.

• Hierocles, fl. 2nd century AD, Stoic philosopher, author of Elements of Ethics
• Apollonius of Chalcedon, was Stoic tutor to the Emperor Marcus Aurelius, during his youth.
• Sextus of Chaerona, fl. 160 AD, Stoic lecturer who taught Marcus Aurelius, and was the nephew of Plutarch.
• Junius Rusticus, c. 100 – 170 AD, highly-distinguished Stoic philosopher and personal tutor of Marcus Aurelius, who provided Marcus with his copy of the lectures (probably the Discourses) of Epictetus.

Marcus Aurelius, 121 – 180 AD, was Roman Emperor and a student of Stoicism, who attended lectures by Stoic teachers, but seems most influenced by his reading of Epictetus’ Discourses, although they did not meet.  Marcus, Epictetus, and Musonius may perhaps be seen as representing one tradition in Roman Stoicism, perhaps different to that represented by Seneca, their predecessor, whom none of them mention in the surviving literature.  The lectures of Musonius and Epictetus were transcribed in Greek, the language used by Marcus in composing his Meditations.  Seneca, however, like Cicero, his predecessor, wrote only in Latin.

We don’t hear much about the Stoics after the death of Marcus Aurelius.  Hence, Stoicism was gradually superseded by Neoplatonism, whose main pioneer was Plotinus, 205 – 270 AD, which was, in turn, ultimately eclipsed by Christianity.