Celsus

A Platonic author who lived in the later half of the 2nd century and wrote a work debunking Judaism and Christianity. His work have not survived and all that we know of him and his teachings come from Origen's Contra Celsum, in which the latter quotes him substantially.

Celsus appears to be the first pagan author to take Christianity seriously at an intellectual level. By combining Platonic monotheism and traditional Greco-Roman polytheism, he argued that Christianity was un-necessary. According to Gerald Bray, "Celsus did not destroy Christianity. On the contrary, he embraced its main ideas and adjusted his philosophy to cope with them — thereby revealing that the new religion had gained the upper hand intellectually and could introduce major modifications in the accepted philosophical notions of his time" (Creeds, Councils & Christ, 89).