Theophrastus was a Greek philosopher who lived from approximately 371 to 287 BCE. He was born in Eresus on the island of Lesbos and moved to Athens for his education. There, he first studied under Plato and later became the principal student and close associate of Aristotle. Upon Aristotle’s death, Theophrastus was named his successor and became the second head of the Peripatetic school at the Lyceum, a position he held for about 35 years. Under his leadership, the school flourished and grew significantly. Like his teacher, he faced political difficulties in Athens related to Macedonian influence and spent a short time in exile before returning.

He was an extraordinarily prolific writer. Ancient sources credit him with over 200 treatises covering nearly every branch of philosophy and science, including logic, metaphysics, ethics, and physics, though most are now lost. His most famous surviving works are on botany: Inquiry into Plants and Explanations of Plants. These texts represent the most systematic and influential botanical studies from the ancient world. Other important surviving works include the Characters, a series of short sketches of flawed personality types, and fragments on metaphysics, logic, and sensory perception.

Theophrastus’s historical importance is twofold. First, as Aristotle’s immediate successor, he was crucial for preserving, developing, and in some cases questioning Aristotelian philosophy, thereby ensuring the survival and influence of the Peripatetic school. Second, through his specialized scientific works, particularly in botany, he made lasting empirical contributions. His botanical texts remained authoritative for centuries, and his Characters influenced later comic and ethical writing. According to modern scholars, his doxographical works also played a key role in preserving the ideas of earlier philosophers for later generations.