During the reign of Antoninus Pius (138-161 AD) Justin ministered in Rome, founding a school that attracted a wide variety of students, including Tatian from Nisibis in Assyria, Irenaeus from Smyrna and Theophilus from near the Euphrates. There he vigorously opposed the Cynic philosopher Crescens, the Gnostic Valentinians, the Marcionites and the Jews. Justin earned his surname when he perished during the persecution of Christians by Marcus Aurelius (121-180AD) in about 165 AD.
For him Christianity was theoretically the true philosophy and practically a new law of holy living and dying.
Thou didst empty the cup of the wisdom of the Greeks, and thou didst thirst yet again, till thou camest unto the well where thou foundest water springing to eternal life. And having drunk deeply thereof, thou didst also drink the cup that Christ gave to His disciples. Wherefore, O Justin, we praise thee as a philosopher and Martyr of Christ.