The Greek philosopher Plotinus (205-270) was the founder of the Neoplatonic school of philosophy, which became the most formidable rival of Christianity in the declining years of the ancient world.

Plotinus was born perhaps in the Egyptian town of Lyco, or Lycopolis. He turned to philosophy at the age of 28 and studied for 11 years with the eminent philosopher Ammonius Saccas at Alexandria.

In 243, desiring to learn about Eastern philosophy, Plotinus joined the expedition led by the Roman emperor Gordian III against the Persians. However, Gordian was murdered, and Plotinus was forced to flee to Antioch and then Rome.

Upon his arrival in Rome, Plotinus began to take students, and his influence in the city soon became great among both professional philosophers and other intellectuals. The emperor Gallienus held Plotinus in such high esteem that he considered founding a philosophers' city in Campania on the ruined site of an...