One of the principal schools of medical philosophy in ancient Greece and Rome. It developed in Alexandria between 270 and 220 B.C., the only one to have any success in reviving the essentials of the Hippocratic concept. The Empiricists declared that the search for ultimate causes of phenomena was vain, but they were active in endeavoring to discover immediate causes. The "tripod of the Empirics" was their own chance observations (experience), learning obtained from contemporaries and predecessors (experience of others), and, in the case of new diseases, the formation of conclusions from other diseases which they resembled (analogy). Empiricism enjoyed sporadic continuing popularity in later centuries up to the nineteenth. (From Castiglioni, A History of Medicine, 2d ed, p186; Dr. James H. Cassedy, NLM History of Medicine Division).