Celsus in the context of "Criticism of Christianity"

Erasistratus (/ˌɛrəˈsɪstrətəs/; Ancient Greek: Ἐρασίστρατος; c. 304 – c. 250 BC) was a Greek anatomist and royal physician under Seleucus I Nicator of Syria. Along with fellow physician Herophilus, he founded a school of anatomy in Alexandria, where they carried out anatomical research. As well, he is credited with helping to found the methodic school of teachings of medicine in Alexandria whilst opposing traditional humoral theories of Hippocratic ideologies. Together with Herophilus, he is credited by historians as the potential founder of neuroscience due to his acknowledgements of nerves and their roles in motor control through the brain and skeletal muscles.

Furthermore, Erasistratus is seen as one of the first physicians/scientists to conduct recorded dissections and potential vivisections alongside Herophilus. The two physicians were said by several Roman authors, notably Augustine, Celsus, and Tertullian, to have performed controversial vivisections on criminals to study the anatomy and possible physiology of human organs while they were in Alexandria. Because of their research, Erasistratus and Herophilus were heavily criticized for their utilization of vivisections; specifically, by the author Tertullian who followed Christian values. Erasistratus and Herophilus are thought to be the only physicians to perform systematic dissections on the human body until the Renaissance.

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.

Against Celsus (Ancient Greek: Κατὰ Κέλσου, Kata Kelsou; Latin: Contra Celsum), preserved entirely in Greek, is a major apologetics work by the Church Father Origen of Alexandria, written in around 248 AD, countering the writings of Celsus, a pagan philosopher and controversialist who had written a scathing attack on Christianity in his treatise The True Word (Λόγος Ἀληθής, Logos Alēthēs). Among a variety of other charges, Celsus had denounced many Christian doctrines as irrational and criticized Christians themselves as uneducated, deluded, unpatriotic, close-minded towards reason, and too accepting of sinners. He had accused Jesus of performing his miracles using black magic rather than actual divine powers and of plagiarizing his teachings from Plato. Celsus had warned that Christianity itself was drawing people away from traditional religion and claimed that its growth would lead to a collapse of traditional, conservative values.

Origen wrote Contra Celsum at the request of his patron, a wealthy Christian named Ambrose, who insisted that a Christian needed to write a response to Celsus. In the treatise itself, which was aimed at an audience of people who were interested in Christianity but had not yet made the decision to convert, Origen responds to Celsus's arguments point-by-point from the perspective of a Platonic philosopher. After having questioned Celsus's credibility, Origen goes on to respond to Celsus's criticism with regard to the role of faith in Christianity, the identity of Jesus Christ, the allegorical interpretation of the Bible, and the relation between Christianity and traditional Greek religion.