Philosopher, Scholar, Mathematician, Agronomist, Naturalist (c.371 BC – c.287 BC)

Theophrastus was Aristotle’s greatest and most beloved student, as well as his successor as headmaster of the Lyceum. Together with his teacher, he is considered as the Father of Botanic and Mineralogy. An Aristotelian philosopher with profound knowledge on various scientific fields, he continued his teacher’s work, becoming one of the most influential philosophers of Greek history.

Theophrastus was originally a student of Plato, before studying next to Aristotle, who gave him the name Theophrastus for his eloquence. He became the first headmaster of the Botanical Garden, founded by Aristotle, next to the river Ilisos in Athens. There, Theophrastus taught botany and phytology. With the death of Aristotle, Theophrastus was appointed headmaster of the Peripatetic School and inherited Aristotle’s library. Furthermore, he undertook custody of Aristotle’s son and was offered to marry his daughter. He lived his whole life primarily in Athens, devoted himself to the Lyceum, where he made a great fortune and was highly respected.

Like Aristotle, he was a polymath and a prolific writer, having written about 250 books, most of which have seen lost. In general, Theophrastus did not decline much from Aristotle’s philosophy, let alone introduce something new to his philosophy. Nevertheless, he developed numerous sciences, most importantly Aristotelian logic and added some new concepts to philosophy. While he is mostly known for his advances in logic, Theophrastus’ contributions are found in a vast number of seemingly unrelated fields such as ethics, metaphysics, music, religion, rhetoric, physiology, geometry, biology, zoology, phytology, poetry and law.

Of note are his contributions in phytology, the science of plants. He wrote 9 books on the history of plants (Peri Phyton Historiae) and 6 books on the causes of plants (Peri Phyton Aetiae), which is a continuation of the former. In it, the philosopher attempts to interpret the causes of the difference of plants with each other. The treatise features over 550 different species of plants from the Mediterranean to the East, each with its own detailed description. Theophrastus also proceeds to an incredibly detailed classification of plants, trees and bushes. Moreover, the treatise contains phytogeography, information on the longevity and the diseases of plants, their fruits, their medicinal powers as well as poisons, making it concurrently a pharmacological treatise. He was the first to use botanical definitions and nomenclature and the first to describe that leaves were used in the nutrition of the plant. He was involved with the study of plants that were brought to Greece from Asia by Alexander the Great during his expeditions. Theophrastus compiled studies of significant value and planted many in his Botanical Garden. Numerous new plants were introduced in Greece thanks to him, namely prunus laurocerasus, rice and cotton.

Other works of importance were Peri Lithon (On Rocks), which was part of a treatise on mineralogy, books on fire, on smell, on wind, on water, on senses and on the colour of animals. Lastly, Theophrastus wrote Characters, a book consisting of 30 chapters, each describing a character, for instance the coward, the oligarch, the inappropriate, the ironic, the vanity, the insolent etc. He provides each one with a background, their social life and their spiritual consistency. It is Theophrastus’ most well-known book.

He had over 2000 students; among them most notably were Demetrius of Phaleron, the founder of the Library of Alexandria, Dicaearchus, a mathematician polymath and Aristarchus of Samos, the astronomer who supposedly founded the heliocentric theory. He died at the age of 85 without having married Aristotle’s daughter, complaining that he was leaving this world right at the time when he was starting to become wise. He had directed the Lyceum for 34 years.


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  3. “Theophrastus”. Helios New Encyclopaedic Dictionary. Passas, I. Athens, 1946. Print.