The published version of Denis Alexander’s 2012 St Andrews Gifford Lectures begins with a straightforward summary: “The purpose of this book is to consider the relationship between genetic variation and human behaviour in the context of ideas about human freedom and determinism.”[p. 1] Taking a biological rather than a philosophical approach, Alexander introduces genetic determinism in contemporary discourse before getting into the nature-nurture debate in Chapters 1–2. In Chapter 3, Alexander presents the development of an integrated approach in contemporary biology, i.e. a subversion of the dichotomous approach covered in the first two chapters. He develops this line of thinking further in Chapter 4 with an alternative approach from contemporary science, and more specifically, the stages of human development. Chapter 5 covers the analogy of gene variation and behavior in animals. Building upon the scientific background covered in the first five chapters, Alexander then looks to behavioral genetics in Chapters 6–10 before getting to the relevant philosophical (e.g. free will) and theological (e.g. image of God) challenges and conversations in Chapters 11–12.

Particularly relevant with reference to natural theology is Alexander’s claim that “those of any faith or none can come to the same or similar conclusions about the topic of free will, simply because experiencing free will is a biological human trait like having two legs –– a brute fact.”[p. 278] It is this brute fact that Alexander then seeks to bring into conversation with theology under five sub-headings: 1) The Image of God is the Whole Person, 2) The Value and Status of Each Human Individual, 3) Subduing the Genome?, 4) The Celebration of Diversity in Community, and 5) Moral Responsibility and Free Will. In the end, Alexander suggests a continuation of the interdisciplinary conversation, noting: “Geneticists, philosophers, sociologists and theologians need to engage with each other more on the challenging subject of free will, at least in an attempt to understand each other’s ‘language game’, and again to bring conceptual clarity to the discussion.”[p. 301]