Porphyry of Tyre (
Greek ???f?????, A.D. 234–c. 305) was a
Neoplatonic philosopher who was born in
Phoenicia.
[1] He is particularly important for the
history of philosophy because he edited and published the
Enneads, the only collection of the work of his teacher
Plotinus. He also wrote many works himself on a wide variety of topics,
[2] some of which have been influential. His
Isagoge, or
Introduction, is an introduction to logic and philosophy,
[3] and in Latin translation it was the standard textbook on logic throughout the
Middle Ages.
[4] In addition, through several of his works, most notably
Philosophy from Oracles and
Against the Christians, he was involved in a controversy with a number of
early Christians,
[5] and his commentary on
Euclid's
Elements was used as a source by
Pappus of Alexandria.
[6]Porphyry's parents were Phoenician, and he was born Malchus ("king")[7] in Tyre. His teacher in Athens, Cassius Longinus, gave him the name Porphyrius ("clad in purple"), a punning allusion to the color of the imperial robes. Under Longinus he studied grammar and rhetoric. In 262 he went to Rome, attracted by the reputation of Plotinus, and for six years devoted himself to the study of Neoplatonism. Because of this he became suicidal.[8] On the advice of Plotinus he went to live in Sicily for five years to recover his health. On returning to Rome, he lectured on philosophy and completed an edition of the writings of Plotinus (who had died in the meantime) together with a biography of his teacher. Iamblichus is mentioned in ancient Neoplatonic writings as his pupil, but this most likely means only that he was the dominant figure in the next generation of philosophers. The two men differed publicly on the issue of theurgy. In his later years, he married Marcella, a widow with seven children and an enthusiastic student of philosophy. Little more is known of his life, and the date of his death is uncertain.
Porphyry is best known for his contributions to philosophy. Apart from writing the Aids to the Study of the Intelligibles (Sententiae Ad Intelligibilia Ducentes), a basic summary of Neoplatonism, he is especially appreciated for his Introduction to Categories (Introductio in Praedicamenta), a very short work often considered to be a commentary on Aristotle's Categories, hence the title.[10] According to Barnes (2003), however, the correct title is simply Introduction (e?sa????,)(Isagoge), and the book is an introduction not to the Categories in particular, but to logic in general, comprising as it does the theories of predication, definition, and proof. The Introduction describes how qualities attributed to things may be classified, famously breaking down the philosophical concept of substance into the five components genus, species, difference, property, accident.
As Porphyry's most influential contribution to philosophy, the Introduction to Categories incorporated Aristotle's logic into Neoplatonism, in particular the doctrine of the categories of being interpreted in terms of entities (in later philosophy, "universal"). Boethius' Isagoge, a Latin translation of Porphyry's "Introduction", became a standard medieval textbook in European schools and universities, which set the stage for medieval philosophical-theological developments of logic and the problem of universals. In medieval textbooks, the all-important Arbor porphyriana ("Porphyrian Tree") illustrates his logical classification of substance. To this day, taxonomy benefits from concepts in Porphyry's Tree, in classifying living organisms see cladistics.
