"Contra Celsum" became the most influential of all early Christian apologetics works; before it was written, Christianity was seen by many as merely a folk religion for the illiterate and uneducated, but Origen raised it to a level of academic respectability. Eusebius admired "Contra Celsum" so much that in his "Contra Hieroclem", he declared that "Contra Celsum" provided an adequate rebuttal to all criticisms the church would ever face. The compilers of the "Philokalia" in the fourth century AD relied extensively on "Contra Celsum" and almost one seventh of the entire text of the "Philokalia" is directly quoted from it. Basilios Bessarion (1403–1472), a Greek refugee who fled to Italy after the Fall of Constantinople in 1453, produced the first Latin translation of Origen's "Contra Celsum", which was printed in 1481.