Sextus Empiricus and Greek Scepticism

In Short

This scholarly treatise recovers the history and core philosophical tenets of Greek Scepticism, focusing on the second-century physician Sextus Empiricus and his foundational text, the Pyrrhonic Sketches. Mary Mills Patrick traces the historical development of Pyrrhonism, situates Sextus in his cultural context, and offers a precise English translation of his First Book. The work outlines how Sceptics systematically suspend judgment (epochê) regarding absolute reality, aiming instead for mental unshakeability (ataraxia). Enduring as a careful study of critical philosophy, it demonstrates how ancient modes of doubt laid the groundwork for modern debates on perception, logic, and scientific inquiry.

The Story

The intellectual path of the book unfolds by first establishing the shadowy life and historical background of Sextus Empiricus, examining the sparse historical references that place him late in the second century A.D. Sextus operates in an era where Stoicism, Epicureanism, and various medical schools clash over the possibility of absolute knowledge. By sifting through ancient authorities like Diogenes Laertius and Galen, Patrick sets the stage for Pyrrhonism—not as a doctrine of absolute denial, but as an ongoing attitude of open-ended investigation.

The focus then shifts to the core mechanics of Pyrrhonism through its famous Tropes, or modes of doubt. Scepticism establishes that human beings can never perceive things as they truly are in their objective essence, but only as they appear through changing phenomena. Sextus demonstrates how perception varies drastically depending on the animal species, the individual human condition, environmental circumstances, and cultural habits. A substance like honey tastes sweet to a healthy person but bitter to someone with jaundice; water feels hot to an inflamed limb but lukewarm to a healthy one. Because every claim is relative to the observer and the context, no single perception can claim absolute authority as a criterion of truth.

Expanding this critical lens, the argument turns to Aenesidemus and his tropes against aetiology, which demolish dogmatic theories of cause and effect. Aenesidemus shows that causality has a subjective value rather than an absolute, physical presence in external nature. The text confronts the controversial claim made by earlier Sceptics that Pyrrhonism serves as a direct pathway to the flux philosophy of Heraclitus. Sextus firmly rejects this connection: while Heraclitus dogmatically asserts that contradictory qualities actually belong to the same object, the true Sceptic merely notes that contradictory qualities appear to be present, maintaining a strict suspension of judgment rather than adopting a new dogma.

Finally, the work addresses how a Sceptic actually navigates daily existence without absolute beliefs. Sextus explains that Sceptics do not reject basic sensory phenomena or deny involuntary feelings like hunger or cold. Instead, they live pragmatically according to natural instincts, local laws, custom, and the practical arts. In medicine, Sextus argues that Scepticism aligns best not with the Empirical school, but with the Methodic school, which acts upon immediate bodily feelings without making rash statements about hidden causes. The book concludes that while Pyrrhonism eventually collapsed as a formal movement, its rigorous interrogation of causality and perception anticipated modern critical philosophies like those of Immanuel Kant.

How It Unfolds

The search for Sextus Patrick examines ancient records and Galen's notable silence to place Sextus Empiricus at the close of the second century A.D. She locates the Pyrrhonean School's temporary activity in Rome and its primary home in Alexandria, where its texts were preserved for the Eastern world.

The anatomy of doubt The foundational principles of Pyrrhonism are defined around the core practice of epochê, or suspension of judgment regarding ultimate reality. The treatise explains that Sceptics do not deny immediate sensory appearances, but refuse to make dogmatic assertions about the underlying nature of things.

The ten tropes of perception Sextus organizes the ten classic modes of Pyrrhonean doubt, demonstrating how sensory information varies across species, individuals, and physical conditions. A detailed examination shows how even animals possess complex sensory choice and practical reasoning, humbling human intellectual pride.

Demolishing causality and dogmatism The work explores Aenesidemus's eight tropes against cause-and-effect reasoning, proving that external causality cannot be established on materialistic grounds. It refutes the notion that Scepticism leads directly to Heraclitean dogmatism, emphasizing that noting contradictory appearances is a universal human experience, not a endorsement of underlying contradictions.

Living without dogma The treatise demonstrates how the Sceptic lives practically without absolute beliefs by following natural feelings, customs, and professional training. Sextus aligns Scepticism with Methodic medicine, showing how physicians respond directly to physical symptoms like hunger or cold without speculating on unobservable physical essences.

The People

Sextus Empiricus A second-century philosopher and physician who seeks tranquility (ataraxia) by refusing to make rash assertions about the unknown. He faces constant opposition from dogmatic philosophers, particularly the Stoics, and wants to preserve an open attitude of ongoing inquiry. He ends up defining the definitive textual framework of ancient Greek Scepticism, showing how one can live practically by attending to everyday phenomena without accepting underlying dogmas.

Pyrrho of Elis The legendary founder of the Sceptical tradition who desires complete happiness and freedom from emotional disturbance. Standing against the dogmatic impulse to claim absolute moral or physical truth, he lives a life of deep indifference (adiaphoria) and impassivity (apatheia). His original attitude evolves from a personal practice of ethical detachment into a formalized, systematic methodology of philosophical doubt.

Aenesidemus An influential Sceptic philosopher who aims to dismantle dogmatic claims about cause and effect through his eight specialized tropes against aetiology. He contends with dogmatic physicists who claim to understand hidden natural forces. By showing that causality has a subjective value rather than an objective reality, he anticipates crucial modern debates on human understanding.

Chrysippus and the Stoics The primary intellectual opponents of the Pyrrhoneans, who seek to establish absolute criteria of truth and firm moral dogmas. They stand as the rigid standard against which Sextus directs his sarcasms and logical counter-arguments. Through their insistence on absolute logical proofs, they inadvertently provide the Sceptics with the exact material needed to demonstrate the instability of dogmatic reasoning.

In Its Own Voice

"The aim has been, accordingly, to give a concise presentation of Pyrrhonism in relation to its historical development and the Scepticism of the Academy, with critical references to the French and German works existing on the subject."

Mary Mills Patrick outlines the scholarly objective of her treatise in her opening preface, emphasizing the need for an accessible English study of ancient Pyrrhonism.

"When, however, we ask whether the object is such as it appears to be, while we concede that it appears so and so, we question, not the phenomenon, but in regard to that which is asserted of the phenomenon, and that is different from doubting the phenomenon itself."

Sextus Empiricus clarifies the core Sceptical stance on sensory perception, distinguishing between immediate lived experience and dogmatic claims about reality.

"The great difference between Aenesidemus and Kant is the difference between the materialist and the believer in subjective reality."

Patrick synthesizes the historic importance of Sceptical critique, connecting ancient arguments against causality to modern critical philosophy.

What It's Really About

At its core, this book explores the boundary between human perception and objective reality, asking whether absolute truth can ever be accessed by the human mind. It demonstrates that dogmatic claims to certainty rest on unstable foundations, as every observation is filtered through subject-dependent conditions, physical states, and social habits. Rather than offering a paralyzing nihilism, the text argues that recognizing human ignorance liberates the mind from intellectual rashness and emotional strife. Suspension of judgment (epochê) becomes the true path to inner peace (ataraxia). Ultimately, the book presents Pyrrhonism as a vital discipline of critical thinking—a method that uses reason to reveal the limits of reason itself, ensuring that search for truth remains an active, uncorrupted pursuit.

Why Read It Today

This book will deeply satisfy readers interested in classical philosophy, the history of ideas, and the roots of modern epistemological doubt. Patrick’s prose is clean, direct, and admirably clear, stripping away dense jargon to make ancient philosophical disputes accessible to a modern reader. The text provides a fascinating window into how ancient thinkers grappled with issues that remain central to philosophy today: the reliability of sensory data, the nature of scientific causality, and the psychological burden of demanding absolute certainty.

Readers should be prepared for the formal academic structure of late nineteenth-century scholarship. The introductory chapters rely heavily on meticulous textual analysis, technical terminology, and frequent citations of German and French scholars. Additionally, the translated portions of Sextus Empiricus employ structured, highly repetitive logical formulas that demand patient, active reading. Yet this rigor is precisely what makes the book lingering and valuable. By working through these foundational texts, one gains an enduring appreciation for a tradition that challenged the grand dogmas of antiquity and helped shape the modern critical mind.