Arcesilaus
| Arcesilaus | |
|---|---|
| |
| Office | 3rd scholarch of the Platonic Academy |
| Tradition | Middle Academy skepticism |
| Known for | Founding the Middle Academy |
| Main interests | Skepticism; epistemology |
| School | Platonic Academy |
| Era | Hellenistic philosophy |
| Notable ideas | Suspension of judgment (epochē) |
| Occupation | Philosopher |
| Wikidata | Q73527 |
Arcesilaus (c. 316–241 BC) was an influential Greek philosopher of the Hellenistic period. He became the third head (scholarch) of Plato’s Academy in Athens and transformed the school from doctrinal instruction to skeptical inquiry. Arcesilaus is best known as the founder of Academic “Middle” Skepticism: he argued that certain knowledge is unattainable and that one should suspend judgment (Greek: epochê) on any disputed claim. Unlike Plato or other philosophers, he made no positive assertions of his own, preferring to question every view rigorously. His approach deeply influenced later skeptics and forced rival schools (especially the Stoics) to defend their doctrines, making Arcesilaus a pivotal figure in the history of ancient philosophy.
Early Life and Education
Arcesilaus was born in Pitane, a Greek city in Aeolis (modern western Turkey), around 316 BC. He received a broad education in his youth: he studied geometry and astronomy in Pitane and even music in Athens. In Pitane he learned mathematics under the astronomer Autolycus, and later studied music with a certain Xanthus when he first arrived in Athens. He then turned to philosophy: initially he trained in rhetoric under Theophrastus (Aristotle’s successor at the Lyceum), to his guardian’s considerable displeasure. However, Arcesilaus soon abandoned rhetoric to join Plato’s Academy.
At the Academy he studied under Crantor and then under the school’s leaders Polemo and Crates of Athens, who succeeded one another as scholarchs. Arcesilaus became known for his quick wit and skill at debate. After Crates’s death around 264 BC, Arcesilaus succeeded him as scholarch of the Academy—a post he held for roughly 25 years. As head of the school, he led by example and shunned the honors and politics of his day. He preferred a simple life devoted to teaching and learning. For instance, when the Macedonian king Antigonus II visited Athens, Arcesilaus reportedly stayed home rather than flatter him. He was also notable for his generosity and modesty: sources say he quietly gave money to students and friends in need and treated everyone, rich or poor, with kindness. Under Arcesilaus the Academy became famous for spirited discussion and inquiry rather than for political alliances or esoteric doctrines.
Philosophical Work and Ideas
Arcesilaus’s philosophy marked a decisive turn toward skepticism in Plato’s Academy. Inspired by Socrates’ method of questioning, he argued that reliable, certain knowledge of the world is impossible to attain. He pointed out that any philosophical thesis could be met with an equally plausible antithesis, leaving true resolution out of reach. Because so many arguments of equal weight stood in opposition, he believed a rational person should refrain from declaring any belief true. This attitude of universal doubt and reservation became his signature stance.
In practice, Arcesilaus urged that we suspend judgment (epochê) on all non-obvious matters. He would neither affirm nor deny contentious propositions about reality, morality, or the gods. Instead of dogmatic assertions, he would say something like “I cannot know this for certain.” To illustrate the unreliability of perception, Arcesilaus used puzzles from everyday experience. A famous example he posed was the question of whether a straight stick appears bent when partly submerged in water. If someone said it looks bent, Arcesilaus would ask how one can trust the eyes when they are so easily deceived. If the person said it looks straight, Arcesilaus would challenge how the mind could ignore the visible bending. Either answer seemed to undermine the certainty of sense knowledge. For Arcesilaus, encountering such paradoxes showed that sense impressions (and even logical proofs) could not deliver absolute truth.
He often targeted the Stoics’ claims of an infallible criterion of truth, demonstrating that their premises could lead to contradiction. At the same time, Arcesilaus insisted that a person need not be paralyzed by doubt. While suspending belief about ultimate truths, one could still act by following what appears sensible or natural. He proposed that our guiding principle should be to eulogon (acting “according to the reasonable”): doing what seems rational and fitting at the moment. This idea was his answer to critics who accused skepticism of leading to apathy or paralysis. Arcesilaus maintained that a wise person lives by what seems reasonable and lets nature guide action, without ever claiming to possess certain knowledge.
Although he emphasized doubt, Arcesilaus did not dismiss everyday life or morality. He held that we may follow ordinary rules of conduct provisionally, guided by reason and natural inclination, even while withholding assent to any absolute claims. This nuanced mix of healthy skepticism and practical living became a defining feature of Academic skepticism. In sum, Arcesilaus’s ideas centered on testing all claims to knowledge, revealing contradictions, and refusing to commit to any fixed dogma. His arguments, as preserved by later writers, consistently show that if equally convincing reasons support both sides of a question, one should withhold judgment.
Method
Arcesilaus followed a dialectical method modeled on Socrates’ style of inquiry. He never promoted a fixed doctrine but engaged his students and opponents in question-and-answer debates. In such discussions, he would first have a speaker state a view, then patiently examine it from all angles. Importantly, he used only the interlocutor’s own accepted assumptions and premises, pushing them to their logical conclusion. This often revealed hidden contradictions or forced the opponent to accept untenable implications.
Throughout these exchanges Arcesilaus himself remained skeptical and never publicly committed to a position on the issue at hand. By resisting the temptation to make any assertion, he maintained a stance of neutral inquiry. Ancient sources describe him as the first to argue both sides of a question; he actually aimed to keep every alternative open. His questioning style could leave his interlocutors in a state of puzzlement (aporia), much as Socrates aimed to do in Plato’s dialogues.
In effect, Arcesilaus turned Plato’s dialogues into an instructional model: philosophers should emulate Socrates by exposing error through cross-examination rather than by delivering lectures or doctrines. This rigorous pursuit of doubt—continually testing beliefs rather than endorsing them—became the hallmark of his method. His dialectical approach defined the skeptical Academy: skeptical argumentation meant engaging with “dogmatic” opponents of other schools, dismantling their claims without offering new dogmas of his own.
Influence
The skeptical revolution Arcesilaus led impacted both his own school and other philosophical traditions. In the Academy, he inaugurated what later writers called the Middle Academy or New Academy, a period defined by critical inquiry instead of metaphysical speculation. Under his leadership, students like Lacydes and Telecles continued in his skeptical vein. The best-known successor, Carneades (mid-2nd century BC), further developed Academic skepticism and famously took it to Rome.
Arcesilaus’s critiques also provoked responses from rival schools. By challenging Stoic epistemology, he forced the Stoics to sharpen their theories of perception and knowledge. For example, the Stoic philosopher Chrysippus wrote multiple works refuting Skeptic arguments—works that survive only in fragments and indirect reports. In this way, Arcesilaus helped refine the Stoic view even as he criticized it.
Outside the Academy, his methods resonated with the Pyrrhonian skeptics active in the same era. Though Pyrrho and Arcesilaus headed different schools, both emphasized suspension of belief and the avoidance of dogma. It is unclear whether Arcesilaus personally knew Pyrrho, but their ideas ran in parallel lines of doubt through Hellenistic philosophy.
Later, when Roman intellectuals took up Greek philosophy, Arcesilaus’s influence was felt through their writings. In particular, the Roman statesman Cicero recorded many Academic arguments in his work Academica, effectively transmitting Arcesilaus’s ideas to the Roman world. Cicero sometimes mocked skepticism, but he preserved Arcesilaus’s major objections to Stoicism and other schools. Likewise, the later skeptic Sextus Empiricus mentioned the Academic skeptics (calling them “Arcesilaeans”) centuries later, even though by then the Academy had evolved under Carneades.
In all, Arcesilaus set the tone for centuries of philosophical debate. He established a tradition that valued inquiry and doubt as much as previous philosophers had valued axiomatic knowledge. His insistence on continued questioning challenged all dogmas and encouraged rigorous argument. Through his impact on students, critics, and later thinkers, Arcesilaus helped shape the skeptical strand of ancient philosophy.
Critiques
Arcesilaus’s skeptical stance attracted many criticisms from contemporaries and later philosophers alike. The Stoics, confronted by his arguments, were especially vocal. They accused him of intellectual “paralysis,” arguing that total doubt would make any action impossible. Chrysippus, the leading Stoic logician, even wrote treatises “Against” Arcesilaus, asserting that if Arcesilaus claims nothing can be known, then he must at least know that claim—an obvious self-contradiction. More broadly, critics charged that skepticism undermined the purpose of philosophy: if we admit nothing can be known, then philosophy and ethics lose their foundation.
In dialogue, Arcesilaus had an answer: he maintained that the skeptic could still live well by following nature and reason in practice, even while remaining agnostic about final truths. He argued that one need not make firm assertions to function in life; instead, one could accept what appears reasonable at each moment. By this view, skepticism did not lead to hopelessness or immorality, because the skeptic could act in accordance with what seems best without claiming certainty.
Within the Platonic tradition, Arcesilaus was also seen by some as having gone too far. By the 1st century BC, the philosopher Antiochus of Ascalon rejected Academic skepticism and revived what he called Dogmatic Platonism. Antiochus argued that Plato and Aristotle did teach knowable truths, and that Arcesilaus had misinterpreted their example by casting doubt on everything. According to Antiochus, it was possible to establish certain principles of knowledge and value (for instance, moral truths) after all.
Modern scholars still debate how far Arcesilaus intended to go. Some interpret him as a relentless debater with no private doctrine (a “pure” dialectical skeptic), while others think he may have believed on balance that knowledge is unattainable. Critics have pointed out practical difficulties in his position: can anyone truly suspend all belief without eventually relying on some assumptive guide in action? At the very least, Arcesilaus’s stance raises questions about whether skepticism itself can be coherently maintained.
Even so, many acknowledge that his challenges were valuable. By systematically exposing hidden assumptions in the dogmatic philosophies of his time, Arcesilaus forced other schools to clarify their positions. His insistence on argument compelled thinkers to refine their logic and evidence. In this light, Arcesilaus can be credited with sharpening philosophical debate, even if some view his skepticism as too sweeping to endorse fully.
Legacy
Arcesilaus is remembered today as the founder of the skeptical tradition within the Platonic Academy. Historians of philosophy often mark the Academy’s history by three eras, and Arcesilaus’s leadership defines the Middle (or New) Academy—a period of doubt and intensive questioning. He essentially shifted Platonism from searching for positive answers to systematically critiquing every claim. Although he wrote nothing systematic, his impact endured through those he influenced. Later skeptics in the Academy and beyond carried on the spirit of inquiry he championed.
His emphasis on continual examination of beliefs foreshadowed some aspects of modern critical thought. In Western philosophical history, his name is not as famous as Socrates or Descartes, but his approach survives wherever philosophy prizes doubt. By underscoring that any claim can be contested, Arcesilaus left a legacy of vigilance: we should keep questioning, even (or especially) when answers seem certain. This legacy of careful scrutiny helped set the stage for subsequent discussions about knowledge and skepticism in later centuries.
Selected Works
Arcesilaus left no surviving philosophical treatises. In fact, ancient writers note that he seemed to have written very little, possibly because he saw absolute conclusions as impossible. One account says he never even composed a formal book. He may have edited some of his teacher Crantor’s works without publishing them or even destroyed what he did write. What few writings of his remain are literary rather than philosophical. For example, a handful of epigrams (short poems) are attributed to him, including a surviving epigram praising King Attalus I of Pergamum. But no philosophical treatise by Arcesilaus is quoted by any ancient author. Rather, his arguments survive only indirectly: through the works of students like Pythodorus, the refutations of opponents (especially Stoics), and later compilers such as Cicero and Sextus Empiricus. In short, there are no original Arcesilaus texts to list; his ideas live on only in the writings of others who discussed him.
Timeline
- c. 316 BC – Arcesilaus is born in Pitane (Aeolis, in what is now Turkey).
- c. 295 BC – After schooling in Pitane (geometry, astronomy) and rhetoric training under Theophrastus in Athens, he joins Plato’s Academy to study philosophy.
- c. 264 BC – Arcesilaus becomes scholarch (head) of the Academy, succeeding Crates of Athens. He inaugurates the skeptical Middle Academy.
- c. 241 BC – Arcesilaus dies in Athens after leading the Academy for over two decades; he is succeeded by Lacydes as scholarch.