Later Pyrrhonism

Historical Context and Sources

Later Pyrrhonism designates the Roman‑era revival and systematization of Pyrrhonian skepticism, a philosophical outlook originally associated with Pyrrho of Elis (c. 360–270 BCE). While early Pyrrhonism is known largely through hostile or second‑hand reports, later Pyrrhonism is comparatively well documented, above all through the works of Sextus Empiricus (fl. late 2nd–early 3rd century CE).

The movement appears to have been revived in the 1st century BCE by Aenesidemus, who broke with the then‑dominant Academic Skepticism of the Platonic Academy and claimed allegiance to Pyrrho. Aenesidemus is credited with formulating the influential Ten Modes (or tropes) of skepticism, though his own works are lost and known mainly through later summaries.

Between Aenesidemus and Sextus, Pyrrhonism seems to have persisted as a loosely organized tradition rather than a formal school with fixed institutional structures. Some later modes, especially the so‑called Five Modes of Agrippa, are attributed to an otherwise obscure skeptic Agrippa, whose historical identity remains debated. By the time of Sextus Empiricus, Pyrrhonism had come to present itself as a comprehensive alternative to both dogmatic schools (such as Stoicism, Epicureanism, Aristotelianism) and to Academic Skepticism.

Sextus’ key works, Outlines of Pyrrhonism and the treatises grouped under Against the Mathematicians (or Adversus Mathematicos), constitute the primary sources for later Pyrrhonism. They offer a systematic exposition of skeptical method and apply it across logic, physics, ethics, and a wide range of specialized disciplines.

Core Doctrines and Methods

Later Pyrrhonism does not present itself as a doctrine about how things are, but as a skill or attitude of inquiry. Sextus defines the skeptic as someone “who is still investigating” (zetētikos). Three interconnected notions are central:

1. Epochē (ἐποχή, suspension of judgment)
   When the skeptic finds arguments for and against a claim to be equipollent (isostheneia), they suspend judgment, neither affirming nor denying the claim. This is not a one‑time conclusion but an ongoing response to philosophical and theoretical disputes. The Pyrrhonist rejects assertions about what exists or what is true by nature (physis), while accepting that things appear a certain way.

2. Living by appearances (phainomena)
   Later Pyrrhonists sharply distinguish between:

   • How things appear (for instance, honey appears sweet), and
   • What things are by nature (whether honey is sweet in itself).

   The skeptic refrains from the latter kind of claim but acknowledges and follows appearances. Sextus describes four guides to life that do not require dogma:

   • Nature’s guidance (e.g. basic perceptions and impulses),
   • The compulsion of feelings (e.g. hunger, thirst, pain),
   • Laws and customs (nomos) of one’s community,
   • Instruction in arts and skills (technai), like medicine or navigation.

3. Ataraxia (ἀταραξία, tranquillity)
   In earlier skeptical tradition, tranquillity was often regarded as the goal of skepticism. Later Pyrrhonists are more cautious: Sextus presents ataraxia as a contingent outcome of the skeptical stance rather than a dogmatically asserted highest good. By suspending judgment about competing theories of what is good or bad by nature, the skeptic is said to become less disturbed by dogmatic disputes and anxieties about ultimate reality.

Methodologically, later Pyrrhonism employs sets of modes (tropoi) designed to generate epochē:

• Ten Modes of Aenesidemus: These stress the variability of perception and judgment across species, individuals, senses, circumstances, positions, mixtures, and customs. From such variability, the skeptic infers that no single perspective can be privileged with certainty.

• Five Modes of Agrippa: Often regarded as more radical and abstract, they include:

  • Disagreement (diaphōnia) among experts,
  • Infinite regress (apeiria) in justification,
  • Relativity (pros ti) of all appearances,
  • Hypothesis (hypothesis) as unjustified starting points,
  • Circularity (diallelus) in arguments.

  These modes directly target the structure of justification and have been seen as ancestors of later epistemological skepticism.

Crucially, Pyrrhonists insist that their own claims are “reported” rather than dogmatically asserted. When they say, for example, “nothing can be known,” they treat this not as a thesis about reality but as an expression of how things currently appear to them in the course of ongoing inquiry.

Ethical Orientation and Way of Life

Ethically, later Pyrrhonism is practical and therapeutic rather than theoretical. It does not propose a positive doctrine of the good life but offers a way of reducing disturbance associated with rigid beliefs. By suspending judgment on questions such as “What is the good by nature?” or “Is pleasure the highest good?”, the skeptic aims to avoid the emotional turmoil that, according to Pyrrhonists, often arises from dogmatic commitment.

The Pyrrhonist does not withdraw from ordinary life. Sextus emphasizes that the skeptic:

• Eats, sleeps, works, and participates in civic life,
• Obeys laws and customs,
• Practices crafts and professions (including, in Sextus’ case, medicine), all without holding theoretical beliefs about the ultimate justification of those practices. Thus later Pyrrhonism presents itself as compatible with ordinary conduct, while treating philosophical theories as occasions for suspension rather than assent.

Critics, ancient and modern, question whether such a life is coherent. They argue that any consistent action seems to presuppose at least some beliefs about the world and about what is better or worse. Pyrrhonists reply that one can be affected by appearances and follow them in a non‑dogmatic way, experiencing fear, desire, and preference without asserting that these reactions track objective values.

Reception and Influence

In late antiquity, later Pyrrhonism coexisted with other philosophical schools but seems not to have had a large, continuous institutional base. Its direct line of succession as an organized school is uncertain, but its textual legacy, especially through the transmission of Sextus Empiricus, proved significant.

During the Renaissance and early modern period, Latin translations of Sextus had a major impact on European thought. Figures such as Montaigne, Descartes, and Hume engaged with Pyrrhonian themes, sometimes adopting them as a challenge to be answered, sometimes as a resource for their own skepticism. The Agrippan modes influenced later discussions of infinite regress and circularity in justification, and the Pyrrhonian focus on disagreement anticipated modern concerns about pluralism and the limits of reason.

In contemporary philosophy, later Pyrrhonism is studied as a sophisticated form of ancient skepticism, raising enduring questions about belief, rationality, and the possibility of living without dogma. Some interpreters view it as a radical challenge to the assumption that life must be guided by theoretical commitments, while others regard its stance as unstable or practically unlivable. The debate over these issues continues to make later Pyrrhonism a central reference point in the history of skeptical thought.