Porphyry

Porphyry of Tyre was a Neoplatonist philosopher who studied in Athens, became Plotinus' pupil in Rome and later edited his teacher's writings as the Enneads. His short introduction to Aristotle's Categories, the Isagoge, raised but deliberately left open the question whether genera and species exist in reality or only in thought. Through Boethius's Latin translation and commentary, that question set the terms of the medieval debate over universals.

Key ideas

• Are genera and species real, are they bodily or incorporeal, and do they exist apart from sensible things? He posed these questions without settling them.
• Classification can be arranged as a tree of genera and species divided by differences.
• Aristotle's logic can be taught as a preparation for Platonist philosophy.
• He argued against eating animals on philosophical and ethical grounds.

Major works

• Isagoge (Εἰσαγωγή)
• On the Life of Plotinus and the Order of His Books
• On Abstinence from Animal Food (De Abstinentia)
• Against the Christians (lost; fragments)

In the conversation

• Reading group Reading group: Porphyry’s Isagoge and the three questions he refused to answer Siobhán Keane · 6 replies
• Reading group Reading group: Plotinus, “On Beauty” (Ennead I.6), the treatise he is said to have written first Mona Fathy · 5 replies