This is a revised edition of a study first made by Dr. John Knox in 1935. His purpose then, as now, is to demonstrate how important a letter this is, and how much light it has to throw on the inclusion of so much Pauline material in the New Testament. The major point of the essay is to show that there is sound reason for the opinion that it was the position of importance achieved eventually in the Christianity of Asia, (as Bishop of Ephesus) by the former slave Onesimus which accounts for the inclusion of Philemon in the primitive collection of the Pauline letters. Dr. Knox's argument is earnestly made, and his scholarship and disciplined imagination will commend his study to other students and scholars. For them it is intended, and they'd better know their Greek if they would get the most out of it.