What is Ancient Skepticism?
In the modern world, a “skeptic” is someone who doubts a particular claim. In ancient philosophy, Skepticism (Skepsis) was a comprehensive way of life and a method of inquiry. The word literally means “searching” or “examining.” For the ancient skeptics, the path to tranquility (Ataraxia) lay not in finding the truth, but in achieving Epoché—the suspension of judgment.
There were two main schools of skepticism in the ancient world: Pyrrhonism and Academic Skepticism.
1. Pyrrhonism: The Path to Silence
Founded by Pyrrho of Elis (c. 360–270 BCE) and later developed by Sextus Empiricus, Pyrrhonism was the more radical of the two schools.
The Goal: Ataraxia
Pyrrho observed that people suffer from anxiety because they are constantly worried about which of their beliefs are “true” or “right.” He suggested that if we stop trying to decide, we will find ourselves in a state of calmness.
The Method: Isostheneia (Equipollence)
To achieve suspension of judgment, the Pyrrhonist uses “Modes” (arguments) to show that for every reason we have to believe X, there is an equally strong reason to believe not-X. When two arguments are of equal weight, the mind naturally “rests” and stops deciding. This is called Isostheneia.
The Pyrrhonist Modes
Sextus Empiricus recorded “Ten Modes” of skepticism, including:
- Differences in Animals: A dog perceives a smell differently than a human; who is “right”?
- Differences in Humans: One person finds a room warm, another finds it cold.
- The Relativity of Position: An oar looks bent in the water but straight in the air.
- Regress/Circular Reasoning: To prove a claim, you need a criterion. To prove the criterion, you need another criterion, leading to an infinite regress.
Living without Belief
A common criticism was: “If you don’t believe anything, how do you live? Do you walk off cliffs?” The Pyrrhonists replied that they live by “appearances” and “customs.” They don’t claim to know the honey is sweet, but it appears sweet to them, so they act accordingly without committing to its “true” nature.
2. Academic Skepticism: The Impossibility of Knowledge
This school developed within Plato’s Academy during its later years, led by figures like Arcesilaus and Carneades.
The Socratic Root
The Academic skeptics took Socrates’ claim “I know nothing except that I know nothing” to its logical extreme. They spent their time refuting the “dogmatic” claims of other schools, particularly the Stoics.
Probability (Pithanon)
Unlike the Pyrrhonists, who suspended judgment on everything, some Academic skeptics (like Carneades) argued that while we can never have certainty, some beliefs are more probable or “persuasive” than others. This allowed them to make practical decisions while remaining philosophically skeptical.
The Fall of the Academy
Academic Skepticism eventually faded as the Academy returned to more “dogmatic” interpretations of Plato, but its influence remained a permanent thorn in the side of subsequent philosophers.
Skepticism vs. Stoicism & Epicureanism
The three great Hellenistic schools all shared the same goal: Ataraxia (peace of mind).
- Stoics found peace in Reason and Virtue.
- Epicureans found peace in Pleasure and Atoms.
- Skeptics found peace in Giving up the search for certainty.
The Legacy of Ancient Skepticism
The writings of Sextus Empiricus were rediscovered during the Renaissance, triggering the “Skeptical Crisis” of the 16th and 17th centuries. Philosophers like Michel de Montaigne and René Descartes had to grapple with these ancient arguments. Descartes’ “Methodological Doubt” was an attempt to use the skeptics’ own tools to find a foundation that was finally “beyond doubt.”
Even today, skepticism remains the “conscience” of philosophy, reminding us of the limits of human reason and the dangers of dogmatism.