Definition
Origen (c. 185-254 AD) was the most influential early Christian theologian of the Alexandrian school and founder of systematic Christian theology. His major work On First Principles (Peri Archōn) contains the most developed early Christian defense of apokatastasis. In 553 his teachings — particularly the pre-existence of souls and the universal restoration vision — were condemned by the Second Council of Constantinople.
Usage in the Corpus
Stephen Jones
Jones places Origen in his genealogy of theologians who defended apokatastasis, together with Clement of Alexandria and Gregory of Nyssa. For Jones, the condemnation of Origen is a historical mistake that cut the Western church off from the apostolic teaching for fifteen centuries. Origen functions in Jones as a legitimizing patristic authority for his own restorationism — not as a critically-weighed source, but as proof that the teaching of the restoration of all things was already taught in the early church.
Origin
Origen was head of the catechetical school in Alexandria and later in Caesarea. His works survive partly in Latin translations by Rufinus and Jerome (the reliability of which translations is disputed). The exact content of his apokatastasis doctrine is therefore partly uncertain. His posthumous condemnation (after his death, 254) is separate from his life as a respected church teacher.