c. 130-c. 70 B.C.

Greek Philosopher, Astronomer, and Mathematician

The most important contribution of Geminus to mathematics was his classification of mathematical disciplines, and his efforts to define both mathematics and science. He also gave his own version of Euclid's parallel postulate, and wrote a survey of Greek astronomy. Much of his work as mathematician and astronomer, however, was in service to his primary career as a Stoic philosopher intent on justifying the Stoic worldview against attacks on the sciences by Epicureans and Skeptics.

Most likely Geminus came from the Greek island of Rhodes, a center of astronomical study. Though his name was Latin, he was not of Italian background; rather, the world in which he lived was one completely dominated by Rome. Geminus studied under Posidonius (c. 135-c. 51 B.C.), and though the latter was only slightly older than he, Posidonius had a reputation as, if not...