On First Principles by Origen of Alexandria, written around 220-230 AD, is one of the most important and contentious works of early Christianity. It provoked controversy when written, provoked further debate when translated into Latin by Rufinus in the fourth century, and was the subject, together with its author, of condemnation in the sixth century. As a result, the work no longer survives intact in the original Greek. We only have the complete work in the Latin translation of Rufinus,

"Behr's translation is literal without being wooden or cumbersome. In keeping with the original languages, some sentences are long, but they are readable. Some detailed footnotes remain to guide readers." - Christopher A. Stephenson, Religious Studies Review