Greeting in God, my most excellent sir, and venerable son Gregory, from Origen. A natural readiness of comprehension, as you well know, may, if practice be added, contribute somewhat to the contingent end, if I may so call it, of that which any one wishes to practise. Thus, your natural good parts might make of you a finished Roman lawyer or a Greek philosopher, so to speak, of one of the schools in high reputation. But I am anxious that you should devote all the strength of your natural good parts to Christianity for your end; and in order to this, I wish to ask you to extract from the philosophy of the Greeks what may serve as a course of study or a preparation for Christianity, and from geometry and astronomy what will serve to explain the sacred Scriptures, in order that all that the sons of the philosophers are wont to say about geometry and music, grammar, rhetoric, and astronomy, as fellow-helpers to philosophy, we may say about philosophy itself, in relation to Christianity.