c. 335-c. 400

Greek Mathematician and Astronomer

The career of Theon, whose daughter was Hypatia of Alexandria, signifies the twilight of scholarship in antiquity. His commentaries on the work of Euclid and Ptolemy, written for the less adept among his students, indicate the declining quality of the ancient academies. Likewise his writings are largely bereft of original thinking, containing rather a summation of the progress that had taken place in much more intellectually vital eras.

Theon's life can be dated by a number of occurrences, including the solar eclipse he witnessed on June 16, 364, as well as a lunar eclipse on November 25 of that year. He also compiled a list of Roman consuls, which he continued to update until 372. A resident of Alexandria for his entire life, he apparently was a member of the Museum, a scholarly society dedicated to scientific research. The latter ceased to...