372-287 BC

Portrait of TeophrastusTheophrastus was a Greek philosopher who wrote on the classification of plants. He was a student of Plato and a friend of Aristotle. He succeeded Aristotle as the head of the Peripatetic School at the Lyceum in Athens. Theophrastus led the school for more than three decades and wrote extensively on philosophy and the natural sciences.

Theophrastus is known for his empirical studies of the natural world and for his plant classification systems. His book Etiology of plants covers plant physiology. In his nine-volume book entitled Inquiry Into Plants and growth of plants, Theophrastus compiled a detailed listing of medicinal herbs, describing formulas, recipes and usages.

In his book called The Characters, Theophrastus developed a taxonomy of undesirable personality traits. The book offers thirty descriptive sketches of different personality types, with each sketch describing a different negative character type. Included in the problematic characters are: The ironical man, the flatterer, the garrulous man, the boor, the complaisant man, the reckless man, the chatty man, the gossip, the shameless man, the penurious man, the gross man, the unseasonable man, the officious man, the stupid man, the surly man, the superstitious man, the grumbler, the distrustful man, the offensive man, the unpleasant man, the man of petty ambition, the mean man, the boastful man, the arrogant man, the coward, the oligarch, the late learner, the evil speaker, the patron of rascals, and the avaricious man (Theophrastus, 1870)

On the Opinions of the Physical Philosophers, a treatise about philosophical schools of thought, was the major source of study for later philosophers.

Theophrastus (1870). The Characters. Retrieved on March 1, 2010.