With Augustine we reach the culmination of fourth-century Christian theories of friendship, for it is he who arguably provides the most profound views, touching on many areas of Christian life and doctrine and according a crucial role to friendship in each Christian's progress towards salvation. And yet Augustine, as much as any of the late antique personalities discussed in this book, accepted the legitimacy of many of the theories developed by philosophers and other observers of human nature in Greek and Roman antiquity. Was this because the Classical formulations on the subject of philia/amicitia were merely elegantly expressed clichés, common and acceptable to most cultures? No, although often expressed in memorable and oft repeated form, the ideas on friendship developed in Greece and Rome stand out in the history of ideas because of their sophistication and because of the importance attached to them, as is clear from a wide variety of literary genres. But even these facts would not explain why friendship suddenly became once again a crucial concept among so many of the Christian writers in the fourth century, for Christians were under no obligation to accept everything from their pagan heritage and in fact would only accept such ideas after close scrutiny. Why did these leading Christians decide to adopt or adapt so many of the theories familiar to them from their traditional Classical education, clearly finding them relevant to their own circumstances and even helpful in exploring the implications of their total commitment to Christ?