Theophrastus of Eresos : Father of Botany and Ecology

Michael Lahanas

Θεόφραστος ο Ερέσιος

... after Aristotle observed that one swallow doth not a Spring make (EN I.7), Theophrastus set to work on a treatise entitled "On the Number of Swallows Needed to Make a Spring, Dorothea Frede

Around 320 BC the Greek philosopher Theophrastus begins the science of botany with his books De causis plantarum/The Causes of Plants and De historia plantarum/The History of Plants. In them he classifies 500 plants, develops a scientific terminology for describing biological structures, distinguishes between the internal organs and external tissues of plants, and gives the first clear account of plant sexual reproduction, including how to pollinate the date palm by hand.

Theophrastus (or Theophrast or Theophrastos) (371 or 372 -287/286) BC, the son of Melantas, born in Eresos on Lesbos, was a student of Aristotle and succeeded him as a director of the Lyceum in Athens. He took over the philosophy of Aristotle in parts reshaping, commenting, and developing it in an original way. His thinking leads to empirism by means of observation, collection, and classification. He was around 35 years the director of the Lyceum and he was a teacher of up to 2000 students.

His true name was Tyrtamos of Eresos, Due to his oratory talents he was nicknamed Euphrastos, the well-spoken, eventually to become famous as Theophrastus, divine spoken. Having joined Plato’s Academy at the age of 17 he soon fell to Aristotle’s spell and accompanied him, still a young man, in his self-chosen exile on the Troad then on his home island Lesbos. He then disappeared from the record for three or more years – during which time some believe he traveled far, to Crete and Libya to come again at Aristotle’s side in Stageira. From there on he never again left his master except for his short last exile, succeeding him as the headmaster of the peripatetic school until his death in 287, at the venerable age of 85. He is said to have been a congenial chap, sworn bachelor and gourmet, and to have died of the sequels of the wedding party of one of his pupils.

The main innovation of Theophrastus is his attempt to find a connection between the „first principles“ (the intelligible world, ratio) and the perceivable objects of nature; this distinction remains the main motive of occidental philosophy during the next two millenia with different solutions.

Theophrastus is also called „father of botany“ and can be regarded as the founder of ecology, too. He described the origin of plants from seeds, he carried out germination experiments, discussed the influence of abiotic habitat factors on plants, the ecology of domestic plants, pollination of plants with the example of the fig, he invented a growth form terminology which is still valid (root, shoot). He described more than 500 species and varieties of plants from lands bordering the Atlantic and Mediterranean. He classified plants into trees, shrubs, under shrubs, and herbs. He noted that some flowers bear petals whereas others do not, and observed the different relative positions of the petals and ovary. In his work on propagation and germination, Theophrastus described the various ways in which specific plants and trees can grow: from seeds, from roots, from pieces torn off, from a branch or twig, or from a small piece of cleft wood.

Paracelsus influenced by Theophrastus

With respect to nature philosophy he postulates disorder in nature and stresses that supposed order has to be proved, he is an adherent of Anaximander and Heraclitus

"...For Theophrastus records, that Violets, Roses, and Gilli-flowers, if they be not well heeded, in three years will wax white, and the experience thereof I myself have plainly seen..."

" Theophrastus says, the wine whereof causes untimely births, and if the Dogs eat the grapes, they will bring forth abortives..."

"...And Theophrastus says, that the flower of the herb Lotum, is not only open and shut, but also sometimes hides, and sometimes shows here stalk for sunset to midnight, and this, says he, is done about the river Euphrates..."

The first reference to the pyroelectric effect is in writings by Theophrastus in 314 BC, who noted that tourmaline becomes charged when heated.

Theophrastus discovers the Sunspots (observed also independently and much earlier in China) Great Moments in the History of Solar Physics

Other publications that survived, some in fragments

On rocks ( περὶ λίθων), Characters (χαρακτῆρες), On fire (περὶ πυρός), On scents, On winds ( περὶ ἀνέμων), On signs of weather.

An important work is:

The Natural History of Plants, (περὶ φυτικῶν ἱστοριῶν α’-θ’ ) a nine books work (with the following topics):
1. The anatomy of plants

2 – 5. Wooden plants

6. Herbaceous perennial plants

7. Vegetables and their cultivation

8. Cereals

9. Saps and medicine


and also

About the Reasons of Vegetable Growth (περὶ φυτικῶν αἰτιῶν α’-ς’) (6 books)


Theophrastus in contrast to Aristotle believed that the animals are capable of reasoning. He considered that as the animals are above the plants it is not ethical to eat meat. For this reason he was a vegetarian. , Τὰ μετὰ τὰ φυσικά , Publications according to Laertius


On Rocks” and “On Winds” are the titles of two books of Theophrastus. Today Greeks say for a less serious discussion or publication that it is “On winds and on water.”

Theophrastus’ book "on Stones", written in the fourth century BC, is the earliest known work on minerals, their properties, and applications. The book is full of interesting information compiled in a clear, easy-to-read style. The excerpt examined in this article is especially important, as it represents the first known mechanochemical reaction, as well as the first description of any process for obtaining a pure metal from a compound. Laszlo Takacs


British Ceramic Transactions 1 April 2004, vol. 103, no. 2, pp. 65-70(6) , Lang S.B, A 2400 year history of pyroelectricity: from Ancient Greece to exploration of the solar system


Pyroelectricity was probably first observed by the Greeks more than 24 centuries ago. The philosopher Theophrastus wrote that lyngourion (most likely the mineral tourmaline) had the property of attracting straws and bits of wood. For two millennia the peculiar properties of tourmaline were more a part of mythology than of science. In the eighteenth century pyroelectric studies made a major contribution to the development of our understanding of electrostatics. In the nineteenth, research on pyroelectricity added to our knowledge of mineralogy, thermodynamics and crystal physics. Pyroelectricity gave birth to piezoelectricity in 1880, and to ferroelectricity in 1920. The field of pyroelectricity flourished in the twentieth century with many applications, particularly in inf rared detection and thermal imaging. Pyroelectric sensors have been carried on many space missions and have contributed significantly to our astronomical knowledge.

Theophrastus Lunar Crater


Time is the most valuable thing one can spend.

Reports in Greek

Θεόφραστος, Χαρακτήρες

Θεόφραστος : Διογένης Λαέρτιος, Βίοι και γνώμαι των εν φιλοσοφία ευδοκιμησάντων



Laszlo Takacs - Quicksilver from Cinnabar: The First Documented Mechanochemical Reaction?

The Characters of Theophrastus

William W. Fortenbaugh, Robert W. Sharples, Michael G. Sollenberger, Theophrastus of Eresus: On Sweat, on Dizziness and on Fatigue , Leiden: Brill, 2003. Pp. 324. ISBN 90-04-12890-5. . (Review)

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