Leo the Mathematician, the Grammarian or the Philosopher (‹See Tfd›Greek: Λέων ὁ Μαθηματικός or ὁ Φιλόσοφος, Léōn ho Mathēmatikós or ho Philósophos; c. 790 – after January 9, 869[1]) was a Byzantine philosopher and logician associated with the Macedonian Renaissance and the end of the Second Byzantine Iconoclasm. His only preserved writings are some notes contained in manuscripts of Plato's dialogues. He has been called a "true Renaissance man"[2] and "the cleverest man in Byzantium in the 9th century".[3] He was archbishop of Thessalonica and later became the head of the Magnaura School of philosophy in Constantinople,[4] where he taught Aristotelian logic.