Nothing for certain is known of Celsus. Origen endeavours to make him out to be an Epicurean, as prejudice existed even among the heathen against this school of philosophy, which denied, or left as open questions, the existence of a God, Providence, and the Eternity of the Soul. He says in his first book that he has heard there had existed two Epicureans of the name of Celsus, one who lived in the reign of Nero († A.D. 68), the other under Hadrian († A.D. 138), and it is with this latter that he has to do. But it is clear from passages of Celsus quoted by Origen, that this antagonist of Christianity was no Epicurean, but belonged to that school of Eclectics which based its teaching on Platonism, but adopted modifications from other schools. Origen himself is obliged to admit in several passages of his controversial treatise that the views of Celsus are not Epicurean, but Platonic; but he pretends that Celsus disguised his Epicureanism under a pretence of Platonism. Controversialists in the first days of Christianity were as prompt to discredit their opponents by ungenerous, false accusation, as in these later days. We know neither the place nor the date of the birth of Celsus. That he lived later than the times of Hadrian is clear from his mention of the Marcionites, who only arose in A.D. 142, and of the Marcellians, named after the woman Marcella, who, according to the testimony of Irenaeus,(74) first came to Rome in the time of Pope Anicetus, after A.D. 157. As Celsus in two passages remarks that the Christians spread their doctrines secretly, because they were forbidden under pain of death to assemble together for worship, it would appear that he wrote his book Λόγος ἀληθής during the reign of Marcus Aurelius (between 161‐180), who persecuted the Christians. We may therefore put the date of the book approximately at A.D. 176.