a physician of Julis, a town of the island of Ceos, now Zea, off Cape Sunium, in Attica, who seems to have flourished from about 300 to 258 B.C. He was grandson of Aristotle, his mother being daughter of that philosopher. He seems to have been in high favour at the court of Seleucus Nicanor, whose son Antiochus he is said to have recovered from a dangerous illness in somewhat extraordinary manner. Antiochus was violently enamoured of his mother-in-law Stratonice, but seeing no prospect of honourably succeeding in his desires, he determined to rid himself of life. His physician Erasistratus easily discovered that his distemper was love, but found it difficult to conjecture who was the object. By close observation however he soon perceived that Stratonice was the cause of his illness; and having informed his father, that monarch was so fond of his son that he allowed him to marry her.

In his old age he renounced the practice of medicine, and, retiring to Alexandria, devoted himself more particularly to the study of anatomy. His description of the brain and nerves is said to have been far more correct than that of any of his predecessors. He was the founder of a school of medicine, which flourished long at Smyrna, and the numerous disciples of which, under the name of Erasistae, continued to exist till the time of Galen, upwards of 400 years. He is mentioned in several passages of the ancient authors Suidas; Strabo, x. 480; Plutarch, Demetr. 38; Appian, Syr. 59.