There are special times of movement in the history of ideas, and one such time - as the author of this study shows - was the second half of the second century, when Christian thought showed fresh vigour. By concentrating on five seminal Christian thinkers of the second century (Justin, Athenegoras, Irenaeus, Clement of Alexandria, and Tertullian), Eric Osborn illustrates how it was that Christianity made monotheism axiomatic to its central doctrinal claims while adapting, too, to the peculiar circumstances in which it developed. The stimulus for new thought came from the objections of the...