Celsus (; , Kélsos; ) was a 2nd-century Greek philosopher and opponent of early Christianity. His literary work, The True Word (also Account, Doctrine or Discourse; Greek: ), survives exclusively in quotations from it in Contra Celsum, a refutation written in 248 by Origen of Alexandria. The True Word is the earliest known comprehensive criticism of Christianity. Hanegraaff has argued that it 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. Philosophy All that is known about Celsus personally is what comes from the surviving text of his book and from what Origen says about him. Although Origen initially refers to Celsus as an Epicurean, his arguments reflect ideas of the Platonic tradition, rather than Epicureanism. Origen attributes this to Celsus's inconsistency, but modern historians see it instead as evidence that Celsus was not an Epicurean at all. Joseph Wilson Trigg states that Origen probably confused Celsus, the author of The True Word, with a different Celsus, who was an Epicurean philosopher and a friend of the Syrian satirist Lucian. Celsus the Epicurean must have lived around the same time as the author of The True Word and he is mentioned by Lucian in his treatise On Magic. Both Celsus the friend of Lucian and Celsus the author of The True Word evidently shared a passionate zeal against superstitio, making it even easier to see how Origen could have concluded that they were the same person. Stephen Thomas states that Celsus may not have been a Platonist per se, but that he was clearly familiar with Plato. Celsus's actual philosophy appears to be a blend of elements derived from Platonism, Aristotelianism, Pythagoreanism, and Stoicism. Wilken likewise concludes that Celsus was a philosophical eclectic, whose views reflect a variety of ideas popular to a number of different schools. Wilken classifies Celsus as "a conservative intellectual", noting that "he supports traditional values and defends accepted beliefs". Theologian Robert M. Grant notes that Origen and Celsus actually agree on many points: "Both are opposed to anthropomorphism, to idolatry, and to any crudely literal theology." Celsus also writes as a loyal citizen of the