Celsus was a 2nd century opponent of Christianity, known to us mainly through the reputation of his literary work, The True Word (or Account), almost entirely reproduced in excerpts by Origen in his counter-polemic Contra Celsum of 248, seventy years after Celsus wrote.

In that year, though the Church was under no widespread persecution, owing to the inertia of the emperor Philip the Arab, the atmosphere was full of conflict. Rome was celebrating the 1000th anniversary of its founding, and imperial aspirations and ideas were naturally prominent. Over against the state and the worship of the Caesar stood as usual the Christian ideal of a rule and a citizenship not of this world, to which a thousand years were but as a day.

A supernatural pride was blended with a natural anxiety, and it was at this juncture that Origen brought to light again a book written in the days of Marcus Aurelius. Sometimes quoting, sometimes paraphrasing, sometimes merely referring, Origen reproduces and replies to all Celsus' arguments. His work shows many signs of haste, but he more than compensates for this by the way in which he thus preserves a singularly interesting memorial of the 2nd century. When we remember that only about one-tenth of The True Word is really lost and that about three-quarters of what we have is verbatim text, it would be ungracious to carp at the method.

Celsus opens the way for his own attack by rehearsing the taunts levelled at the Christians by the Jews. Jesus was born in adultery, and nurtured on the wisdom of Egypt. His assertion of divine dignity is disproved by his poverty and his miserable end. Christians have no standing in the Old Testament prophecies, and their talk of a resurrection that was only revealed to some of their own adherents is foolishness. Celsus indeed says that the Jews are almost as ridiculous as the foes they attack; the latter said the saviour from Heaven had come, the former still looked for his coming.

However, the Jews have the advantage of being an ancient nation with an ancient faith. The idea of an Incarnation of God is absurd; why should the human race think itself so superior to bees, ants and elephants as to be put in this unique relation to its maker? And why should God choose to come to men as a Jew? The Christian idea of a special providence is nonsense, an insult to the deity. Christians are like a council of frogs in a marsh or a synod of worms on a dunghill, croaking and squeaking, "For our sakes was the world created".

It is much more reasonable to believe that each part of the world has its own special deity; prophets and supernatural messengers had forsooth appeared in more places than one. Besides being bad philosophy based on fictitious history, Christianity is not respectable. Celsus does not indeed repeat the Thyestean charges so frequently brought against Christians by their calumniators, but he says the Christian teachers who are mainly weavers and cobblers have no power over men of education. The qualifications for conversion are ignorance and childish timidity. Like all quacks they gather a crowd of slaves, children, women and idlers.

I speak bitterly about this, says Celsus, because I feel bitterly. When we are invited to the Mysteries the masters use another tone. They say, Come to us ye who are of clean hands and pure speech, ye who are unstained by crime, who have a good conscience towards God, who have done justly and lived uprightly. The Jews say, Come to us ye who are sinners, ye who are fools or children, ye who are miserable, and ye shall enter into the kingdom of Heaven: the rogue, the thief, the burglar, the poisoner, the despoiler of temples and tombs, these are their proselytes. Jesus, they say, was sent to save sinners; was he not sent to help those who have kept themselves free from sin? They pretend that God will save the unjust man if he repents and humbles himself. The just man who has held steady from the cradle in the ways of virtue He will not look upon.

He pours scorn upon the exorcists — who were clearly in league with the demons themselves — and upon the excesses of the itinerant and undisciplined prophets who roam through cities and camps and commit to everlasting fire cities and lands and their inhabitants. Above all Christians are disloyal, and every church is an illicit collegium, an insinuation deadly at any time, but especially so under Marcus Aurelius. Why cannot Christians attach themselves to the great philosophic and political authorities of the world? A properly understood worship of gods and demons is quite compatible with a purified monotheism, and they might as well give up the mad idea of winning the authorities over to their faith, or of hoping to attain anything like universal agreement on divine things.

Celsus and Porphyry are the two early literary opponents of Christianity who have the most claim to consideration, and it is worth noticing that, while they agree alike in high aims, skillful address and devoted toil, their sophy of religious standpoints are widely dissimilar. Porphyry is mainly a pure philosopher, but also a man of deep religious feeling, whose quest and goal are the knowledge of God; Celsus, the friend of Lucian, though sometimes called Epicurean and sometimes Platonist, is not a professed philosopher at all, but a man of the world. He was really an agnostic at heart, like Caecilius in Minucius Felix, whose religion is nothing more or less than the Empire. He is keen, positive, logical; combining with curious dashes of scepticism many genuine moral convictions and a good knowledge of the various national religions and mythologies whose relative value he is able to appreciate.

His manner of thought is under the overpowering influence of the eclectic Platonism of the time, and not of the doctrine of the Epicurean school. He is a man of the world, of philosophical culture, who accepts much of the influential Platonism of the time but has absorbed little of its positive religious sentiment. In his antipathy to Christianity, which appears to him barbaric and superstitious, he gives himself up to the scepticism and satire of a man of the world through which he comes in contact with Epicurean tendencies. He quotes approvingly from the Timaeus of Plato: It is a hard thing to find out the Maker and Father of this universe, and after having found him it is impossible to make him known to all. Philosophy can at best impart to the fit some notion of him which the elect soul must itself develop.

The Christian on the contrary maintained that God is known to us as far as need be in Christ, and He is accessible to all. Another sharp antithesis was the problem of evil. Celsus made evil constant in amount as being the correlative of matter. Hence his scorn of the doctrine of the resurrection of the body held then in a very crude form, and his ridicule of any attempt to raise the vulgar masses from their degradation. The real root of the difficulty to Platonist as to Gnostic was his sharp antithesis of form as good and matter as evil.

Opinion at one time inclined to the view that The True Word was written in Rome, but the evidence (wholly internal) points much more decisively to an Alexandrian origin. Not only do the many intimate references to Egyptian history and customs support this position, but it is clear that the Jews of Celsus are not Western or Roman Jews, but belong to the Orient, and especially to that circle of Judaism which had received and assimilated the idea of the Logos.

The date also is clearly defined. Besides the general indication that the Empire was passing through a military crisis, which points to the long struggle waged by Marcus Aurelius against the Marcomanni and other Germanic tribes, there is a reference (Contra Celsum, viii.69) to the rescript of that emperor impressing on governors and magistrates the duty of keeping a strict watch on extravagances in religion. This edict dates from 176-177, and inaugurated the persecution which lasted from that time till the death of Marcus Aurelius in 180. During these years Commodus was associated in the imperium, and Celsus has a reference to this joint rule (viii.71).

Celsus shows himself familiar with the story of Jewish origins. Any pagan who wished to understand and criticize Christianity intimately had to begin by learning from the Jews, and this accounts for the opening chapters of his argument. He has a good knowledge of Genesis and of the Book of Enoch (v. 52), but does not make much use of the Prophets or the Psalter. As regards the New Testament his position is closely in agreement with that reflected in the contemporary Acts of the Martyrs of Scili. He speaks of a Christian collection of writings, and knew and used the synoptic gospels, but was influenced less by the Gospel of John. There is more evidence of Pauline ideas than of Pauline letters.

The gnostic sects and their writings were well known to him (viii.15 and vi.25), and so was the work of Marcion. There are indications, too, of an acquaintance with Justin Martyr and the Sibylline literature (vii. 53, cp. v.61). He is perfectly aware of the internal differences among Christians, and he is familiar with the various stages of development in the history of their religion. These are cleverly employed in order to heighten the impression of its instability. He plays off the sects against the Catholic Church, the primitive age against the present, Christ against the apostles, the various revisions of the Bible against the trustworthiness of the text and so forth, though he admits that everything was not really so bad at first as it is at present.

The True Word had very little influence either on the mutual relations of Church and State, or on classical literature. Echoes of it are found in Tertullian and in Minucius Felix, and then it lay forgotten until Origen gave it new life. A good deal of the neo-Platonic polemic naturally went back to Celsus, and both the ideas and phrases of The True Word are found in Porphyry and Julian, though the closing of the New Testament canon in the meantime somewhat changed the method of attack for these writers.

Of more importance than these matters is the light which the book sheds on the strength of the Christian Church about the year 180. It is arguable that Celsus had insufficient apprehension of the spiritual inclinations that Christianity claimed to satisfy, and he underrated the significance of the Church, regarding it simply as one of a number of warring sects (mostly Gnostic), and so seeing only a mark of weakness. Yet there is all through an undercurrent which runs against his surface verdicts, and here and there comes to expression. He admits that Christianity has been stated reasonably; against the moral teaching of Jesus he only brings the charge of plagiarism; and with the Christian assertion that the Logos is the Son of God he completely accords.

Most suggestive, however, is his closing appeal to the Christians. Come, he says, don't hold aloof from the common regime. Take your place by the emperor's side. Don't claim for yourselves another empire, or any special position. It is an overture for peace. If all were to follow your example and abstain from politics, the affairs of the world would fall into the hands of wild and lawless barbarians (viii.68). Conceding that Christians are not without success in business (infructuosi in negotiis), he wants them to be good citizens, to retain their own belief but conform to the state religion. It is an earnest and striking appeal on behalf of the Empire, which was clearly in great danger, and it shows the terms offered to the Church, as well as the importance of the Church at the time. Numerically, Christians may have formed perhaps a tenth of the population, i.e. in Alexandria there would be fifty or sixty thousand, but their sway was greater than these numbers suggest.