Lives and Opinions of Eminent Philosophers

1. Introduction

Lives and Opinions of Eminent Philosophers is a ten‑book Greek compendium that combines biographical sketches with reports of doctrines for more than eighty philosophers from early Greek sages to Epicurus. Modern scholars commonly classify it as a work of doxography (reporting philosophical opinions, or doxai) and philosophical biography rather than original philosophy.

The work’s distinctive feature is its systematic pairing of a philosopher’s life—anecdotes, character traits, death stories, wills—with a summary of his teachings, often culminating in short sayings or apophthegms. This format has led many interpreters to treat the work as evidence for how late antique readers conceived philosophy as both a way of life and a body of doctrine.

Because it preserves otherwise lost material on certain schools and figures, especially the Cynics, early Stoics, minor Socratics, and Epicureans, the treatise is regarded as an indispensable—though methodologically problematic—source for the history of ancient philosophy. At the same time, its uncritical juxtaposition of conflicting reports and taste for colorful stories have made it a focal point in debates about the reliability of ancient biographical traditions.

The entry that follows examines the work’s historical setting, authorship, structure, philosophical content, major passages, and subsequent reception within the broader study of Greek philosophy.

2. Historical Context

2.1 Intellectual and Cultural Setting

Most scholars date Lives and Opinions of Eminent Philosophers to the early 3rd century CE, under the Roman Empire. Greek remained the primary language of higher education in the eastern Mediterranean, and there was a strong tradition of compilatory scholarship: lexica, anthologies, and doxographical handbooks that gathered earlier material for educated readers.

The work fits into a late antique interest in philosophical history, alongside writers such as Plutarch, Galen, and later Porphyry, who also combined biography with doctrinal exposition. Unlike technical treatises of contemporary Platonists or Aristotelians, Diogenes’ compilation appears aimed at a broader literate audience interested in philosophical lore, edifying stories, and accessible doctrinal summaries.

2.2 Place within Ancient Histories of Philosophy

Ancient doxography had earlier antecedents (e.g., Theophrastus’ lost Opinions of the Physicists, and the Aëtius tradition). Many scholars see Diogenes as inheriting this genre but expanding it with more biographical detail and anecdote.

Some interpreters situate the work within a broader Second Sophistic culture, noting its rhetorical flourishes and taste for paradoxical tales, while others emphasize continuity with Hellenistic scholarly traditions of cataloguing and excerpting earlier authorities.

3. Author and Composition

3.1 Diogenes Laertius: Identity and Debates

Very little is securely known about Diogenes Laertius himself. His origin, education, and philosophical allegiance remain disputed. The epithet “Laertius” has been linked—speculatively—to the town of Laerte in Cilicia or to a Roman clan name (Laertii). Some scholars infer a non‑philosopher man of letters, given his lack of systematic argumentation, while others suggest he may have had some philosophical training, possibly in Epicurean or skeptical circles, based on sympathetic treatments and certain thematic emphases.

3.2 Date and Circumstances of Composition

Internal references—including apparent allusions to Roman imperial institutions—lead many scholars to place the work around 220–250 CE, though proposed dates range from the late 2nd to early 3rd century. The often‑cited dedication to a woman named Arria rests on a disputed epigram in the preface; some regard it as authentic evidence of a learned Roman patron, others as later interpolation or rhetorical fiction.

The composition is commonly interpreted as a single, planned project, given the consistent division into ten books and a recurring pattern of life‑and‑doctrine presentation. Yet stylistic unevenness and varied depth across books have prompted hypotheses of piecemeal compilation over time or heavier reliance on particularly rich sources for certain schools.

3.3 Sources and Method

Diogenes frequently names earlier authors—such as Favorinus, Sotion, and Antigonus of Carystus—and often collates multiple conflicting reports without adjudication. Scholars debate whether this reflects deliberate source transparency or merely uncritical excerpting. In either case, the work stands as a major witness to otherwise lost Hellenistic histories of philosophy and biographical collections.

4. Structure and Organization

4.1 Division into Ten Books

The treatise is organized into ten books, each roughly centered on particular schools or lines of succession rather than strict chronology. The outline already established in modern scholarship highlights:

This arrangement foregrounds school identity and teacher‑pupil successions (diadochai) as the principal principle of organization.

4.2 Internal Pattern of the Lives

Within individual lives, Diogenes tends to follow a loosely recurring sequence:

1. Origin and lineage (birthplace, parents, civic status)
2. Education and teachers (entry into a school or succession)
3. Anecdotes and character traits
4. Writings and lists of works
5. Doctrinal summary (often short and schematic)
6. Death and posthumous reputation

Not all lives include all elements, and the sequence can vary or be interrupted by digressions, letters, and epigrams. Proponents of a more systematic view see this as a recognizable biographical template; critics emphasize its inconsistency and tendency to mix genres (biography, anthology, catalogues, doxography).

4.3 Use of Catalogues and Successions

Diogenes regularly inserts catalogues of philosophical works and successions of scholarchs. These catalogues often derive from earlier Hellenistic librarians and historians and serve to integrate individual lives into broader institutional histories (e.g., of the Academy or Stoa). Some scholars see this as an early effort at a prosopographical history of philosophy; others note the lack of firm chronological anchors and potential conflation of legendary and historical figures.

5. Central Themes and Philosophical Content

5.1 Life and Doctrine as a Unit

A recurrent theme is the implicit linkage between a philosopher’s character and his teachings. Diogenes juxtaposes moral anecdotes with doctrinal summaries, allowing readers to infer correspondences (e.g., Cynic shamelessness with anti‑conventional ethics). Some interpreters argue that this reflects an ancient conception of philosophy as a bios (way of life), while others caution that the entertaining stories may stem more from popular biographical motifs than philosophical agendas.

5.2 Plurality of Schools and Doctrines

The work presents a wide range of mutually incompatible doxai on physics, ethics, and logic. Diogenes rarely offers explicit evaluation, creating what some view as a pluralistic tableau of Greek philosophy. Others interpret this neutrality as methodological abstention rather than genuine doctrinal ecumenism, pointing to possible Epicurean sympathies in Book 10.

Key doctrinal areas recur:

5.3 School Identity and Succession

Diogenes emphasizes diadochai—the chains of masters and pupils that define schools. Proponents see this as an attempt to conceptualize philosophy historically, in terms of institutional continuity. Critics argue that the successions can be artificial, retroactively imposing school labels on disparate figures.

5.4 Attitudes toward Skepticism and Dogmatism

Book 9’s treatment of Pyrrho and skeptical traditions sits alongside lengthy expositions of dogmatic systems (especially Stoicism and Epicureanism). Some scholars read this juxtaposition as reflecting a late antique awareness of methodological skepticism; others maintain that Diogenes presents skepticism as just one school among others, without highlighting its meta‑philosophical implications.

6. Famous Passages and Key Sources

6.1 Notable Passages within the Work

Several sections of the Lives have become standard reference points:

For example, the Epicurean ethics preserved by Diogenes includes statements such as:

"

“We call pleasure the beginning and end of the blessed life.”

— Epicurus, Letter to Menoeceus (via Diogenes Laertius 10.129)

6.2 Diogenes’ Own Sources

Diogenes draws heavily on earlier, now largely lost, authors. Among those explicitly cited are Sotion, Hermippus, Antigonus of Carystus, Apollodorus of Athens, and Favorinus. Modern scholarship often treats his work as a gateway to these earlier traditions.

There is debate over how faithfully Diogenes reproduces these sources. Some argue that he preserves substantial verbatim material, especially in Book 10; others suggest a more eclectic, redactional role, with omissions, rearrangements, and occasional misunderstandings.

7. Legacy and Historical Significance

7.1 Role in the Transmission of Ancient Philosophy

Lives and Opinions of Eminent Philosophers has been a central conduit for knowledge of Greek philosophy from late antiquity onward. Medieval Byzantine scholars cited and excerpted it, and during the Renaissance it became a key text for humanists reconstructing ancient schools, influencing figures such as Erasmus and Montaigne.

Its importance is particularly marked where other sources are sparse:

7.2 Scholarly Reception and Critique

Modern scholars simultaneously regard the work as indispensable and problematic. Its preservation of lost texts and biographical traditions makes it foundational for the history of ancient philosophy, yet its anecdotal style and lack of critical sifting have raised enduring concerns.

Key lines of assessment include:

• Historiographical value: Some view the Lives as a pioneering, if unsystematic, history of philosophy; others see it more as a literary miscellany than a historical work in a strict sense.
• Reliability: Critics point to contradictions, moralizing stories, and chronological vagueness. Defenders argue that, once its methods and sources are understood, it can be used cautiously and fruitfully.
• Influence on later images of philosophers: The popular modern portraits of figures like Diogenes the Cynic or Heraclitus the “weeping philosopher” owe much to Diogenes’ anecdotes and character sketches, which have shaped both scholarly and popular perceptions.

As a result, contemporary research often treats Diogenes Laertius both as a necessary source and as an object of meta‑historical study, examining how ancient philosophy was remembered, organized, and narrated in late antiquity.