Diophantus the Arab
Diophantus the Arab () was an Arab teacher and sophist at Athens during the 4th century AD. His most famous student was Libanius (336–340). He was active during the reign of Julian the Apostate (361–363).

Diophantus' place of birth within Arabia is unknown. It may have been Petra, also the birthplace of the 5th-century iatrosophist Gessius of Petra and a place associated in some manner with Diophantus' contemporary and fellow sophist, Epiphanius of Syria. He is not listed among the rhetors and sophists of Gerasa by Stephanus of Byzantium.

Diophantus was a pupil of Julian of Cappadocia, whom he succeeded as rhetor (teacher of rhetoric) in Athens. According to Eunapius, who attended his lectures in the period 362–367, Diophantus recruited students from Arabia. He was also accused of kidnapping students. According to Libanius' own account, he went to Athens intending to become a student of Epiphanius of Syria, but was ambushed by enthusiasts of Diophantus who imprisoned him in a cell until he took an oath to become Diophantus' student. His oath to Diophantus did not prohibit him from attending other lectures. Libanius records that his teacher had once also been roughed up by thugs. Diophantus is mentioned in the Byzantine "Suda"'s entry for Libanius.

Another one of Diophantus' rival teachers in Athens was Prohaeresius, on whose death in 367 he delivered a eulogy quoted in part by Eunapius, who considered him far inferior to Prohaeresius. He died not long after. He left behind two sons whom Eunapius describes as devoted to commercial gain and luxurious living.

Diophantus has sometimes been confused with the more famous mathematician, Diophantus of Alexandria, and his ethnic background (Arab) has sometimes been attributed to the latter. He must also be distinguished from the Egyptian philosopher and priest of mysteries of the same name cited by Libanius in a letter of 362.
Q35323
Arab
Concept
Q2355080
sophist
MEDIA
Q1524
Athens
LOC
Q263892
Libanius
PER
Q33941
Julian the Apostate
PER
Q31945
Arabia
LOC
Q5788
Petra
LOC
Q5983472
iatrosophist
Concept
Q97332555
Gessius of Petra
PER
Q11919453
Epiphanius of Syria
PER
Q31565
Gerasa
LOC
Q380881
Stephanus of Byzantium
PER
None
Julian of Cappadocia
UNK
Q81009
rhetoric
Concept
Q343018
Eunapius
PER
Q12544
Byzantine
LOC
Q216299
Suda
LOC
Q385213
Prohaeresius
PER
Q178217
Diophantus of Alexandria
PER
Q202311
Egyptian
LOC
Q505821
mysteries
Concept
Q96376400
Diophantus the Arab
UNK
+4^^http://www.w3.org/2001/XMLSchema#decimal
4
NUMBER
+336^^http://www.w3.org/2001/XMLSchema#decimal
336
NUMBER
+340^^http://www.w3.org/2001/XMLSchema#decimal
340
NUMBER
+361^^http://www.w3.org/2001/XMLSchema#decimal
361
NUMBER
+363^^http://www.w3.org/2001/XMLSchema#decimal
363
NUMBER
+5^^http://www.w3.org/2001/XMLSchema#decimal
5
NUMBER
+367^^http://www.w3.org/2001/XMLSchema#decimal
367
NUMBER
place of birth
occupation