Galen, (130?–201? A.D.), a Greek physician. Galen was one of the greatest physicians of ancient times and is considered the father of experimental physiology.
Herophilus a Greek physician who lived during the late fourth and early third centuries B.C.
Hipparchus (second century B.C.), a Greek astronomer and mathematician. He was born in Nicaea in Asia Minor (modern Turkey).
Hippocrates (460?–377? B.C.), a Greek physician called “the father of medicine.” Nothing reliable is known of his life, but it is said he studied at the temple of Asclepius (god of medicine) on the island of Cos.
Dioscorides, Pedanius, a Greek physician of the first century A.D. His five-volume De Materia Medica, on the use of herbs, was still widely used by botanists and physicians in the Middle Ages.
Ptolemy, or Claudius Ptolemaeus, (90?–168? A.D.), a Greek astronomer and geographer.