Origines Adamantius was an early Christian philosopher and scholar. Educated in Alexandria he spent 28 years teaching and writing. He was so zealous in his faith that he castrated himself for reasons of purity, but was still allowed to preach despite not being an ordained priest. He founded a school in Caesarea that was even more prestigious than that in Alexandria, where even St. Gregory Thaumaturgus was a student.
In the reign of Decius, Origen was imprisoned and died just after his release. He was among the foremost Christian scholars of his day, but often strayed from the church, blending paganism and his own unique views into his teaching.
According to St. Jerome he wrote 800 works but only very few survive. Among the surviving works are letters, apologies, and exegeses. Unfortunately, because of this, most of his work that has passed down in quotes from later writers may be suspect due to philosophical differences.
Hexapla (a critical edition of the bible, not surviving)
De Principiis (On First Principles)
Contra Celsum (Against Celsus)
Various letters and other apologies