Contra Celsum in the context of "Black magic"

Celsus (/ˈsɛlsəs/; Hellenistic Greek: Κέλσος, Kélsos; fl. AD 175–177) was a 2nd-century Greek philosopher and opponent of early Christianity. His literary work The True Word (also Account, Doctrine or Discourse; Greek: Hellenistic Greek: Λόγος Ἀληθής) survives exclusively via quotations in Contra Celsum, a refutation written in 248 by Origen of Alexandria. The True Word is the earliest known comprehensive criticism of Christianity and Judaism.

Hanegraaff has argued that The True Word was written shortly after the death of Justin Martyr (who was possibly the first Christian apologist), and was probably a response to his work. Origen stated that Celsus was from the first half of the 2nd century AD, although the majority of modern scholars have come to a general consensus that Celsus probably wrote around AD 170 to 180.

The Ophite Diagrams are ritual and esoteric diagrams used by the Ophite sect of Gnosticism, who revered the serpent from the Garden of Eden as a symbol of wisdom, which the malevolent Demiurge tried to hide from Adam and Eve.

Celsus and his opponent Origen (Contra Celsum, vi. §§ 24-38) both describe the diagrams, though not in the same way. Celsus describes them as ten separate circles, circumscribed by one circle, the world-soul, Leviathan, divided by a thick black line, Tartarus, together with a square, with words said at the gates of Paradise. Further to this, the Ophites are said by Celsus to add the sayings of prophets, and circles upon circles, with some things written within the two great cosmological circles representing God the Father, and God the Son.

The True Word (or Discourse, Account, or Doctrine; Ancient Greek: Λόγος Ἀληθής, Logos Alēthēs) is a lost treatise in which the ancient Greek philosopher Celsus addressed many principal points of early Christianity and argued against their validity. In The True Word, Celsus attacked Christianity in three ways: by attacking its philosophical claims, by marking it as a phenomenon associated with the uneducated and lower class, and by cautioning his audience that it was a danger to the Roman Empire. Information concerning the work exists only in the extensive quotations from it in the Contra Celsum ("Against Celsus"), written some seventy years later by the Christian Origen. These are believed to be accurate, but may not give a fully comprehensive picture of the original work.

The crucifixion darkness is an event described in the synoptic gospels in which the sky becomes dark in daytime during the crucifixion of Jesus for roughly three hours. Most ancient and medieval Christian writers treated this as a miracle, and believed it to be one of the few episodes from the New Testament which were confirmed by non-Christian sources. Modern scholars have found references by early historians to accounts of this event outside the New Testament, although no copies of the referenced accounts survive.

In his Apologeticus, Christian apologist Tertullian in AD 197 considered this not an eclipse but an omen, which is recorded in Roman archives. In his apologetic work Contra Celsum, the third-century Christian scholar Origen offered two natural explanations for the darkness: that it might have been the eclipse described by Phlegon of Tralles in his Chronicle or that it might have been clouds. In his Chronicle of Theophanes the fifth-century chronicler George Syncellus quotes the History of the World of Sextus Julius Africanus as stating that a world eclipse and an earthquake in Judea had been reported by the Greek 1st century historian Thallus in his Histories.