Near the middle of the second century, Celsus, a heathen philosopher, wrote a professed treatise against Christianity. To this treatise, Origen, who came about fifty years after him, published an answer, in which he frequently recites his adversary's words and arguments. The work of Celsus is lost; but that of Origen remains. Origen appears to have given us the words of Celsus, where he professes to give them, very faithfully, and, amongst other reasons for thinking so, this is one, that the objection, as stated by him from Celsus, is sometimes stronger than his own answer. I think it also probable, that Origen, in his answer, has retailed a large portion of the work of Celsus: “That it may not be suspected,” he says, “that we pass by any chapters, because we have no answers at hand, I have thought it best, according to my ability, to confute every thing proposed by him, not so much observing the natural order of things/as the order which he has taken himself.”

Celsus wrote about one hundred years after the Gospels were published; and therefore any notices of these books from him are extremely important for their antiquity. They are, however, rendered more so by the character of the author; for, the reception, credit, and notoriety of these books must have been well established amongst Christians, to have made them subjects of animadversion and opposition by strangers and by enemies.