In order to understand the development of Christian thought and belief, one must have a thorough grasp of the various ways in which the earliest Christian thinkers interacted with the intellectual milieu in which they lived. Furthermore, it is important to note that the way in which individual Christian authors from the first to the fourth centuries ce looked upon the philosophical tradition of the Graeco-Roman world varied greatly: some openly admired the philosophies of various schools, whereas others were openly hostile. In each case, the philosophical underpinnings of each thinker's thought emerge and thus influence the development of Christian doctrine. This is a fact that must be recognised and understood by anyone wishing to study either early Christianity or the evolution of Christian doctrine.

The second edition of K.'s volume admirably examines the various ways in which the first Christian thinkers interacted, both positively and negatively, with the various philosophical traditions of their day. K.'s methodology is to ‘focus more on the traditional philosophical issues rather than the new ones (such as Christology) which have arisen with Christianity’, and the way in which early Christian thinkers engage with these central philosophical topics (p. 20). The strength of this approach is that it narrows the scope of the work to specifically philosophical topics; as a result the earliest Christian thinkers are considered not as theologians, but rather as philosophers.

K. notes in the introduction that early Christian thinkers had three primary reasons for developing their philosophical positions: first, to expound the claims of Scripture by means of philosophical concepts and argumentation; second, to resolve disputes concerning philosophical questions within Christianity; and third, ‘to defend the Christian faith’ against the arguments of opposing philosophical schools (p. 10). How they did so varies widely, and a particular strength of the work is that it clearly communicates that the views of early Christian philosophers towards philosophy were not clear-cut. The first chapter, which forms the foundation for the following chapters, notes that early Christians were critical of Hellenic philosophy and asserted that it was ‘a failure’ insofar as the philosophical schools were unable to reach the truth. Thus, even someone such as Clement of Alexandria states that philosophy is ‘foolish’, and Lactantius harshly criticises it for failing to arrive at the truth (p. 30). That said, and K. articulates this concisely, early Christians did not reject the philosophical tradition outright: Clement, for example, also praises philosophy as ‘a partial revelation of the Logos’, going so far as to claim that Hellenic philosophy is an indirect revelation of God (p. 36). Indeed, early Christian philosophers would claim that the aim of philosophy was correct, because both Christians and pagans believed that the goal of philosophy is to know oneself, which would in turn lead to knowledge of God; this would guide one in how to live (p. 43).

The following chapters examine five specific topics that were central in ancient philosophy: physics and metaphysics (Chapter 2), logic and epistemology (Chapter 3), free will and divine providence (Chapter 4), psychology (Chapter 5), and ethics and politics (Chapter 6). Each chapter begins with a brief introduction to the subject insofar as it was discussed and debated before Christianity, and it continues with the various Christian responses. Often the responses consist of the views of more than one Christian thinker, particularly when there is a connection between them. To use the divisions introduced in the first chapter, these are often based upon location (such as Clement of Alexandria and Origen), similar views (Theophilus and Tatian) or authors who are fairly contemporaneous (Irenaeus and Tertullian).

A particular strength of the work is that it does not neglect the role of competing views outside of (what is now considered orthodox) Christianity and Hellenic philosophy, namely various Gnostics such as Marcion and the Arians, especially Eunomius. The inclusion of these perspectives adds another layer to the complexity of the development of early Christian philosophy, which in turn is useful for understanding the trajectory that Christian thought would take. The book is also commendable for its clarity and ease of reading: the work flows well from one topic or individual to another, and, although the work is fairly short, it is concise, and leaves readers with a firm grasp not only of how a particular Christian thinker viewed, for example, free will and divine providence, but also how Christian views on the topic progressed. In some chapters attention is given to how the philosophical positions taken by early Christians developed and were employed in later doctrinal debates.

While the book presents a concise description of what early Christian thinkers wrote on these philosophical issues, it would have been helpful for some readers, such as those who have not had a thorough education in ancient philosophy, if the chapter introductions to the pre-Christian history of the topics had been slightly more comprehensive. In addition, some chapters are notably shorter than others, particularly the chapters on ‘Logic and Epistemology’ and ‘Ethics and Politics’. This is naturally due in part to the fact that topics such as cosmogony and free will receive more attention from the Christian thinkers upon whom K. focuses, though more discussion in the chapter on logic would have been useful to understand better the logical and epistemological frameworks in which early Christians operated. Despite the importance of ethics and political life in Hellenic philosophy and its equal importance in Christian thought, the final chapter receives less attention and elaboration than one might expect.

That said, the work is a highly useful and valuable contribution both to the field of early Christian studies and to ancient philosophy in general, particularly the latter. K. provides an excellent introduction to a corner of the intellectual milieu in the ancient world that is often unrecognised or even dismissed, when in fact the rise of Christian thought would play a role in the development of non-Christian philosophy.