Leo the Mathematician
Leo the Mathematician or the Philosopher (Greek: Λέων ὁ Μαθηματικός or ὁ Φιλόσοφος, Léōn ho Mathēmatikós or ho Philósophos; c. 790 – after 869) 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" and "the cleverest man in Byzantium in the 9th century". He was archbishop of Thessalonica and later became the head of the Magnaura School of philosophy in Constantinople, where he taught Aristotelian logic.
Leo was born in Thessaly, a cousin of the Patriarch of Constantinople, John the Grammarian. He was probably at least in part of Armenian descent. In his youth he was educated at Constantinople, but he travelled to the monasteries of Andros, where he could obtain rare manuscripts and was taught mathematics by an old monk. He originally taught privately in obscurity in Constantinople. The story goes that when one of his students was captured during the Byzantine–Arab Wars, the Caliph al-Mamun was so impressed by his knowledge of mathematics that he offered Leo great riches to come to Baghdad. Leo took the letter from the caliph to the Byzantine emperor Theophilos, who, impressed by his international repute, conferred on him a school (ekpaideutērion) in either the Magnaura or the church of the Forty Martyrs.
In the version of the story recorded by Theophanes Continuatus, the caliph, upon receiving Leo's letter of refusal, sent a letter requesting answers to some difficult questions of geometry and astrology, which Leo obliged. Al-Mamun then offered two thousands pounds of gold and a perpetual peace to Theophilos, if only he could borrow Leo's services briefly; the request was declined. The emperor then honoured Leo by having John the Grammarian consecrate him metropolitan of Thessalonica, which post he held from the spring of 840 to 843. There is a discrepancy in this account, however, in that the caliph died in 833. It has been suggested that either the connection between the caliph's final letter and Leo's appointment as metropolitan is in error, or the caliph in question was actually al-Mutasim. This latter option squares with the account of Symeon the Logothete, who makes Leo teach at the Magnaura from late 838 to early 840 and was paid handsomely.
Leo, an iconoclast sometimes accused of paganism, lost his metropolitancy with the end of the Iconoclasm in 843. Despite this, he delivered a sermon favourable of icons within months of Theophilos' death. Around 855, Leo was appointed at the head of a newly established Magnaura School by Bardas. He was renowned for his philosophical, mathematical, medical, scientific, literary, philological, astronomic, and astrological learning, and was patronised by Theoktistos and befriended by Photios I of Constantinople. Cyril was his student. Leo has been credited with a system of beacons (an optical telegraph) stretching across Asia Minor from Cilicia to Constantinople, which gave advance warning of Arab raids, as well as diplomatic communication. Leo also invented several automata, such as trees with moving birds, roaring lions, and a levitating imperial throne. The throne was in operation a century later, when Liutprand of Cremona witnessed it during his visit to Constantinople.
Most of Leo's writings have been lost. He wrote book-length works, poems, and many epigrams, and was also a compiler, who brought together a wide range of philosophical, medical, and astronomic texts. His library can at least partially be reconstructed: Archimedes, Euclid, Plato, Paul of Alexandria, Theon of Alexandria, Proclus, Porphyry, Apollonius of Perga, the lost Mechanics of Quirinus and Marcellus, and possibly Thucydides. He composed his own medical encyclopaedia. Later Byzantine scholars sometimes confused Leo with the scholar Leo Choirosphaktes and the emperor Leo VI the Wise, and ascribe to him oracles.
- Marcus Louis Rautman (2006), Daily Life in the Byzantine Empire (Greenwood Publishing Group, ISBN 0-313-32437-9), 294–95.
- "History of the Pianola". Pianola Institute.
- Holmes, George (1990). The Oxford illustrated history of medieval Europe. Oxford: Oxford University Press. p. 52. ISBN 978-0-19-285435-3.
- Штокало И. З., История отечественной математики. Том 1. С древнейших времен до конца XVIII в., Киев, Наукова Думка, 1966, p. 447
- Философская Энциклопедия [ред. Ф. В. Константинова], Лев Математик, т. 3, Москва, 1964, pp. 156—157
- Trkulja J., Lees C. Armenians in Constantinople, in: Εγκυκλοπαίδεια Μείζονος Ελληνισμού, Κωνσταντινούπολη, 2008
- H. C. Evans, W. D. Wixom, The Glory of Byzantium: Art and Culture of the Middle Byzantine Era, A.D. 843—1261. Metropolitan Museum of Art, New York, 1997, p. 351
- Browning, Robert (1964). "Byzantine Scholarship". Past and Present. 28: 7–8. doi:10.1093/past/28.1.3.
- According to the Pseudo-Symeon, this student was Boïditzes, who betrayed Amorium to the caliph.
- According to Joseph Genesius and Theophanes Continuatus between 829 and 833; Symeon the Logothete makes the caliph al-Mutasim and puts the invitation after the Islamic conquest of Amorium in the fall of 838, cf. Treadgold, Warren T. (1979). "The Chronological Accuracy of the Chronicle of Symeon the Logothete for the Years 813–845". Dumbarton Oaks Papers. 33: 162. doi:10.2307/1291437.
- Symeon says the Magnaura, Continuatus the Forty Martyrs (Treadgold, "Chronological Accuracy ", 186).
- Treadgold, "Chronological Accuracy ", 172.
- Warren T. Treadgold (1997), A history of the Byzantine state and society (Stanford University Press), 447.
- Warren T. Treadgold (1988), The Byzantine Revival, 780–842 (Stanford University Press), 372.
- Treadgold, "Chronological Accuracy ", 187, believes, on the basis of the Logothete's account, that this occurred in 843 and was a re-founding of Theophilos' school.
- Tougher, Shaun (1997). The Reign of Leo VI (886–912): Politics and People. Leiden: Brill. p. 113. ISBN 90-04-10811-4.
- Vlasto, A. P. (1970). The Entry of the Slavs into Christendom: An Introduction to the Medieval History of the Slavs. Cambridge: Cambridge University Press. p. 33.
- Treadgold, Warren T. (1979). "The Revival of Byzantine Learning and the Revival of the Byzantine State". The American Historical Review. American Historical Association. 84 (5): 1245–1266 [p. 1259]. doi:10.2307/1861467. JSTOR 1861467.
- Safran, Linda (1998). Heaven on Earth: Art and the Church in Byzantium. Pittsburgh: Penn State Press. p. 30. ISBN 0-271-01670-1. Records Liutprand's description.
- For a detailed discussion of Leo's telegraph and his automata, see Leone Montagnini (2002), "Leone il Matematico, un anello mancante nella storia della scienza", Studi sull'Oriente Cristiano, 6 (2), 89–108.
- Among them, worthy of special mention are some centos preserved in the Palatine Anthology, see Prieto Domínguez, Óscar (2011), De Alieno Nostrum: el Centón profano en el mundo griego. Estudios filológicos, 328. Salamanca: Ediciones Universidad de Salamanca. ISBN 9788478002085, p. 120-179.