Theophrastus

Quick Facts

• Name: Theophrastus of Eresus
• Lived: c. 371-287 BCE
• Place: Eresus on Lesbos; later Athens
• School: Peripatetic, the school of Aristotle's Lyceum
• Main role: Aristotle's successor as head of the Lyceum
• Known for: botany, character sketches, logic, metaphysics, ethics, and doxography
• Major works: Enquiry into Plants, On the Causes of Plants, Characters, Metaphysics, On Sense Perception

The Big Question

How can Aristotle's way of studying nature, argument, and human life become a working research program without forcing every case into one simple formula?

In One Minute

Theophrastus was Aristotle's close younger colleague and the next head of the Lyceum. He led the school for about thirty-five years and turned Aristotelian inquiry into an organized research culture. His method was practical: collect real cases, sort them carefully, and ask what causes explain them. He is best remembered for systematic botany and for Characters, a set of sharp portraits of bad social habits.

What They Taught

Theophrastus taught that philosophy should investigate the world we actually meet. The Peripatetic school was Aristotle's school at the Lyceum. Under Theophrastus, it did not just repeat Aristotle. It studied plants, animals, weather, language, arguments, moral habits, and the opinions of earlier thinkers.

He kept Aristotle's central question: what kind of explanation makes a thing intelligible? A cause is a "because" answer. Causes can explain what something is made of, what structure it has, what produced it, and what end or function it serves. Theophrastus used this framework cautiously. A plant's growth may depend on seed, soil, water, season, heat, and cultivation. One neat answer may miss the case.

That caution appears in his treatment of purpose in nature. Teleology means explaining something by its end, function, or goal. A root helps a plant take in nourishment. Theophrastus did not reject this kind of explanation, but he resisted using it everywhere. Some natural details may not be "for the sake of" an obvious good.

His botany shows the method at its best. In Enquiry into Plants he asks what plants are like: roots, stems, leaves, flowers, fruits, seeds, habitats, and uses. In On the Causes of Plants he asks why they grow, reproduce, change, and thrive in one place rather than another.

Theophrastus also developed logic, metaphysics, and ethics. Logic is the study of good reasoning; he refined work on propositions and syllogisms, where conclusions follow from premises. In metaphysics, he raised puzzles about first principles and natural explanation. In ethics, he follows Aristotle's virtue ethics: a virtue is a stable good habit, and the "mean" is the right measure between too much and too little. Characters turns that moral interest into portraits of the flatterer, the gossip, and the superstitious person.

Key Ideas With Examples

• Peripatetic inquiry: Aristotle's Lyceum style of research. It starts with observed cases, sorts them into kinds, and asks for causes.
• Classification: grouping things by important similarities and differences. Theophrastus compares roots, fruit, seed, wood, habitat, and use instead of just saying "tree."
• Cause: an explanation of why something is so. A vine bears fruit because of its nature, but also because of season, soil, water, pruning, and heat.
• Teleology: explanation by end or function. A leaf may be explained by what it does for the plant, but Theophrastus warns that not every natural detail has an obvious purpose.
• Botany: systematic study of plants as living things. Theophrastus looks at growth, reproduction, place, food, medicine, timber, gums, and resins.
• Character sketch: a short portrait of a moral type. A flatterer is shown praising, echoing, and adjusting himself to win approval.
• Doxography: reporting earlier philosophers' views. Theophrastus's lost Opinions of the Natural Philosophers became an important source for later knowledge of the Presocratics.

Major Works

• Enquiry into Plants: describes plant parts, reproduction, habitats, cultivation, trees, shrubs, herbs, cereals, juices, gums, resins, and medicines.
• On the Causes of Plants: asks why plants grow, bear fruit, change with climate, and respond to soil, moisture, pruning, grafting, and cultivation.
• Characters: thirty brief sketches of unattractive human types. It matters for ethics, rhetoric, comedy, and later literature because it shows vice as repeated social behavior.
• Metaphysics or On First Principles: a short, puzzle-driven treatise on first principles, change, and the limits of teleology.
• On Sense Perception: reports and analyzes earlier theories of perception, preserving views from Parmenides, Empedocles, Democritus, and Plato.
• On Fire, On Stones, On Weather Signs, On Winds, and On Odours: shorter scientific works, or works preserved under his name, on concrete natural phenomena.
• Opinions of the Natural Philosophers: a mostly lost history of earlier natural philosophy used by later writers on nature, matter, motion, and first principles.

Why It Matters

Theophrastus matters because he shows Aristotelianism becoming a research culture. He preserved and developed Aristotle's project across logic, ethics, physics, biology, rhetoric, politics, and the history of philosophy.

He also made botany into a serious field. Earlier writers noticed plants, used them, and named them. Theophrastus studied their parts, reproduction, habitats, and causes in an ordered way.

Characters gave later writers a model for social observation. His reports on earlier philosophers helped preserve ancient debates that might otherwise be lost.

Proponents, Critics, and Opponents

Theophrastus belongs first with Aristotle. After Aristotle left Athens in 323 BCE, Theophrastus took charge of the Lyceum and led it for about thirty-five years. He inherited the Peripatetic method, but he was not a passive copyist. He tested Aristotle's ideas and filled gaps.

Later Peripatetics treated him as the second great head of the school. His students included Menander, Demetrius of Phalerum, and Arcesilaus.

Stoicism gives the clearest ethical contrast. Theophrastus, like Aristotle, thought virtue is central but that external goods such as friends, health, and decent circumstances still matter for flourishing. Stoics argued that virtue alone is enough for happiness.

Modern readers can criticize the ancient science and the surface-level psychology of some character sketches. Still, the lasting achievement is the method: careful observation, classification, causal explanation, and attention to difficult cases.

Related Pages

• Aristotle
• Aristotelianism
• Natural Philosophy
• Presocratics
• Stoicism