Ichthyas the son of Metallus, was a Greek philosopher and a disciple and successor of Euclid of Megara

Euclid of Megara

Euclid of Megara was a Greek Socratic philosopher who founded the Megarian school of philosophy. He was a pupil of Socrates in the late 5th century BCE, and was present at his death. He held the supreme good to be one, eternal and unchangeable, and denied the existence of anything contrary to the...

 in the Megarian school. He was a colleague of Thrasymachus of Corinth

Thrasymachus of Corinth

Thrasymachus of Corinth, was a philosopher of the Megarian school. Little is known about him except that he was colleague and friend of Ichthyas, and he had presumably been taught by Euclid of Megara, the founder of the school. He was said to have been the teacher of Stilpo.-References:*D. Zeyl,...

 in the school. Ichthyas is described as a man of great eminence, and Diogenes of Sinope

Diogenes of Sinope

Diogenes the Cynic was a Greek philosopher and one of the founders of Cynic philosophy. Also known as Diogenes of Sinope , he was born in Sinope , an Ionian colony on the Black Sea , in 412 or 404 BCE and died at Corinth in 323 BCE.Diogenes of Sinope was a controversial figure...

 is said to have addressed a dialogue to him.

According to Hilarius Emonds, correcting a previously misread passage in Tertullian

Tertullian

Quintus Septimius Florens Tertullianus, anglicised as Tertullian , was a prolific early Christian author from Carthage in the Roman province of Africa. He is the first Christian author to produce an extensive corpus of Latin Christian literature. He also was a notable early Christian apologist and...

's Apologeticus

Apologeticus

Apologeticus or Apologeticum is Tertullian's most famous work, consisting of apologetic and polemic; it was written in Carthage in the summer or autumn of 197 AD, during the reign of Septimius Severus. In this work Tertullian defends Christianity, demanding legal toleration and that Christians be...

, Ichthyas was a leader in the oligarchic revolt in Megara

Megara

Megara is an ancient city in Attica, Greece. It lies in the northern section of the Isthmus of Corinth opposite the island of Salamis, which belonged to Megara in archaic times, before being taken by Athens. Megara was one of the four districts of Attica, embodied in the four mythic sons of King...

 in 375 BCE.