I would like to thank Ken Keathley, Clay Carlson, Michael Ruse and Michael Wittmer for their helpful comments and insights, some of which might need a whole new book to address adequately, but I will do my best here in the space available.

On the topic of books, I should first mention that I have a new book coming out later his year with Cambridge University Press entitled Are We Slaves to Our Genes?. The aim of the book is to be a more popular expression of the main themes of Genes, Determinism and God written for a general readership and with the rapidly moving science thoroughly updated. For those who find the technical genetics somewhat challenging, hopefully this new book will be helpful, and it also covers several topics not addressed in Genes, Determinism and God that have broad societal implications, such as psychiatric genetics and the relationship between genetic variation and bodily size and shape. Of particular relevance to the present discussion, the book also contrasts the power of rival worldviews, in particular those provided by Transhumanism and Christianity, in influencing how new genetic information is used to shape the human future. As a bonus, I am happy to report that it is free of “jaw-breakingly difficult labels.”

Are We Slaves to Our Genes? does address some of the points raised by our present reviewers, though by no means all, so I shall attempt here to focus on those concerns.

Free Will and Determinism

Let us start by biting the bullet or, using Michael Ruse’s vivid metaphor, identifying with the ‘happy little rodent’ stuck in the glue. I included virtually nothing about the philosophy of free will in my Gifford Lectures, very aware that I am not a philosopher and therefore very content to leave that topic to the professionals. But when I sent my Giffords book outline for Genes, Determinism and God to CUP, a reviewer came back with a strong recommendation that there should be more in the book engaging with the philosophy of free will. I therefore delayed submitting the manuscript and spent a happy six months reading my way into at least some of the huge recent literature on the topic, no doubt barely scraping the surface of such a massive iceberg (the books I found most useful at that time are listed in footnote 81 in Genes, Determinism and God).

Cambridge University Press, 2017

A health warning was in the back of my mind when writing about free will. This came from Prof. Peter van Inwagen who spoke at our Faraday Institute Summer Course in 2012 on a “Philosophical Perspective on Free Will.”https://www.faraday-institute.org/Multimedia.php I’d always remembered Prof. Inwagen saying that personally he never started a talk about free will by using a definition, because then he’d immediately lose most of the audience who disagreed with his definition, so he rather chose to speak about it with the hope that some clear ideas might emerge during the conversation.

I should have taken the health warning more seriously, because I note that Ken Keathley has taken my very introductory thoughts on free will (in the Introduction) as a ‘definition,’ whereas the formal definition actually comes a little later in the Introduction: “the ability to intentionally choose between courses of action in ways that make us responsible for what we do” (p. 2). As it happens, I do not think that this definition is particularly controversial—one has to start somewhere, though of course showing that this is demonstrably true is another matter altogether. My approach remains the same now as it did when writing the book: given that the experience of free will, more or less as just defined, is a universal characteristic of humankind, is there anything that we know about in science—genetics in particular—that might make us think that this experience is based on an illusion? My suggested answer to this question in Genes, Determinism and God is clearly “no.”

For the non-professional, reading one’s way into the field (in my case not for the first time, but this was the most focused time) is a frustrating experience. One reason for this is because the various positions on the topic are often set out as if unambiguous and distinct—libertarianism, compatibilism, determinism, and the like. What I really wanted to do when writing the book was to self-label as For the non-professional, reading one’s way into the field (in my case not for the first time, but this was the most focused time) is a frustrating experience. a ‘libertarian compatibilist,’ but reckoned that this would be immediately discarded by philosophers as a fudge, so instead went for the DAME acronym (‘dual-aspect monistic emergentism’) as a way to introduce the discussion. So imagine my delight when, during the time that I was more recently writing Are We Slaves to Our Genes?, a book was published by a professional philosopher, Christian List, entitled Why Free Will is Real (Harvard University Press, 2019), which expressed my own view, or something very close to it, so much better than anything else that I’ve read on the topic. Even better, List states in his introduction that the aim of his book is to defend a position that he calls “compatibilist libertarianism” or, if preferred, “free-will emergentism.”See pp. 9-10. I will therefore henceforth self-label as a ‘libertarian compatibilist,’ holding my head high and referring any questioning of the term to List, who I think does an excellent job in its defense.

Which brings me then to Michael Ruse’s comments on ‘emergentism’, a concept that List seems happy with, but which apparently Ruse is not. It is certainly the case that differing views on the idea of emergentism in philosophy range from outright enthusiasm to downright antipathy—and everything in between. Ruse clearly self-locates at one end of this spectrum. But I agree with him on one point: the idea of mind as being ‘emergent from’ brain is not an explanation as to how this happens—although I suspect this may be tilting at windmills. I don’t know of anyone in the field who thinks that it’s an ‘explanation’. However, I do know of many people (Christian List being one of them) who find it a useful conceptual idea when thinking about the kind of thing that’s going on, even though no one currently knows what exactly is going on (and the brain-mind field is split between those who think we shall never know and those who think that one day we might be able to know). Use of the emergent concept is also useful in interdisciplinary discussions such as this one, since many scientists use it in presenting their results—not as an explanation, but as a useful conceptual idea. For example, a quick check on the 2019 scientific literature (excluding the humanities) shows that the word ‘emergent’ appeared 440 times in the titles of scientific peer-reviewed articles during that one year.

The topic of emergentism brings us to dualism and the helpful comments by Ken Keathley on this topic. I am well aware that dualism has been undergoing something of a renaissance in some philosophical and certainly theological circles in recent years, though possibly more on the US rather than European side of the Atlantic. I am equally aware that we are unlikely to solve our differences on this topic with a brief few comments. And I agree with KeathleyI rather suspect that it all depends on which particular evangelical tradition to which one is referring! that it is not science qua science that can solve the question—which extends heavily into theology and philosophy. In fact, when we have our staff discussions round the table at The Faraday Institute we quickly find that there are equally strong but opposing views on this topic represented round the table! So the discussion is likely to go on for a long time.

Having said all that, I suppose it is worth saying that I have personally been influenced by a strong British evangelical tradition on the topic, represented powerfully by the late Prof. Donald M. MacKay, Scottish neuroscientist and philosopher; by Prof. Malcolm Jeeves, psychologist, still going strong at St Andrews University; and by more recent thinkers in the field such as the late Dr. Peter Clarke from Lausanne and Dr. Stuart Judge from Oxford, both originally PhD students with Prof. Mackay (during which time, as a matter of interest, Dr Judge became a Christian). When I was Editor of the journal Science and Christian Belief, I also well remember the many articles that we published on both sides of the question. Ken Keathley suggests that some issues in Genes, Determinism and God will be “controversial to evangelicals.” I rather suspect that it all depends on which particular evangelical tradition to which one is referring!

As always, one of the problems is the language used and what we really intend to say by the use of that language. Let us say that I am working out a mathematical problem using my computer. The equations and the mathematical formulae in use are all encoded by my computer’s electronics. The mathematics in progress is an emergent phenomenon in relation to the physical processes of the computer, but the mathematics clearly exists independently in its own ‘abstract space’ independently of the physical processes in action. I know of no professional mathematician who is not an instinctive neo-Platonist of some kind. So are the mathematical concepts encoded by my computer a ‘substance’ distinctly different from the electronic ‘substance’ involved in their encoding? It all depends on how the words are defined.

I couldn’t help thinking of this when considering the suggested term ‘emergent dualism’ in relation to the body-mind question. A key question here, as Keathley points out, is: “If this emergent mind truly is irreducible, that is, it cannot be explained in terms of the physical brain, then would not this be better understood as emergentSo I rather suspect that ‘emergent dualism’ and what I have referred to by the DAME mouthful end up referring to essentially the same idea. dualism?” But again I think we’re back to the same point made in response to Ruse: the concept of strong emergence is really not about ‘explaining’ things—such as how mind emerges from a physical brain—but about conceptualizing what is going on in a way that explains the available data, all the time recognizing that there is a huge gap in our understanding of “what is going on.”

So I rather suspect that ‘emergent dualism’ and what I have referred to by the DAME mouthful end up referring to essentially the same idea. But I also suspect that the ‘monism’ word acts as a red flag to those who wish to reject monistic ideas in any shape or form, whereas the ‘dualism’ word has a similar effect on those of us who think that the word can take us into unhelpful territory where a conceptual bog quickly sinks the unwary. But I do think, unlike Michael Ruse, that a coherent and useful discussion can be had about the question, and I don’t think that being a New Mysterian gets us very far in terms of thinking scientifically about behavioral genetics. For at the end of the day, it is simply a fact that human genetic variation has something to do with differential human behaviors—ranging in scale from the relatively trivial to major differences—and we need models that help us get a rational grip on what is going on. DAME was introduced to describe the type of brain-mind interaction that I think serves this purpose well. Pure monism really doesn’t do the job with its implication that brain and mind are identical, when clearly they are not (I do not “argue for monism” despite Keathley’s comment—I argue for DAME, which is something different). That’s why we end up skating along a ‘both-and’ middle way in which the distinctive properties of mind and the distinctive properties of the brain are both taken seriously, albeit with an emphasis on their close connections rather than picturing them as existing in isolated compartments. I am fairly sure that there is no set of words or a single phrase that does a completely adequate job in this respect, but I suspect that DAME is as good as any. And one thing is certain: if ‘strong dualism’ were really the case, with mind and brain envisaged as completely separate entities, then the field of behavioral genetics could certainly not exist.

Some Theological Questions

The Question of the ‘Soul’

Keathley suggests that Alexander “contends that we are only physical beings and that we do not possess a spiritual component typically called the soul.” Well, not really,Let a thousand flowers continue to blossom on this particular topic! and again I think the language used in this discussion can often lead participants off in different directions, when in reality they might find more in common than their use of different words might first suggest. The soul is profoundly spiritual in the sense that the Scriptures, as far as I can see, present humankind made in the image of God as a body and soul-spirit unity (I am very happy with Michael Wittmer’s emphasis here), and it is the soul-spirit aspects that ensure that we humans have the capacity to have fellowship with God as we are saved by faith as a result of the finished work of Christ on the cross. Humans are profoundly spiritual beings, albeit either spiritually alive in Christ, or spiritually dead, not by having a platonic soul ‘plugged in’ like a memory stick is plugged into a physical computer, but because in their very selves they have the wonderful possibility of responding to God’s love by his grace.

Keathley concludes his comments by saying that: “I believe the biblical evidence for the immateriality of the soul to be compelling.” But again we are left with the question as to what “immateriality” really means. Abstract mathematical equations, quarks and minds are all “immaterial” in a certain sense, though all profoundly related to the existence of physical things, and maybe that is just the case with the spirit-soul. However, we are certainly not going to resolve all our differences on the meanings of body and soul and spirit in a few brief exchanges. Let a thousand flowers continue to blossom on this particular topic!

The Imago Dei

Ken Keathley points out, correctly, that I am rather keen on the ‘functional’ view as an interpretive tool when interpreting the Biblical concept ‘image of God.’ I think it will be clear from the text that I have been much influenced by Richard Middleton’s fine book The Liberating Image: The Imago Dei in Genesis 1 (Brazos, 2005) plus some earlier classic texts that emphasize a functionalist interpretation. But it is also the case that I start Chapter 12 on this topic by remarking that: “Interpretations over the past two millennia of what it means for humankind to be made in the image of God have involved substantialist, functionalist, relational, representational, existential and eschatological approaches. I have no intention of reviewing these interpretations here, a task already well done by others [plus a lengthy citations list].” So by no means do I see the ‘functional’ interpretation as the only one that is useful—far from it, I see them all as having a valid point to make, and therefore I happily agree with all the points that Keathley makes on this topic.So by no means do I see the ‘functional’ interpretation as the only one that is useful—far from it, I see them all as having a valid point to make, and therefore I happily agree. Similarly when Wittmer writes: “Why wouldn’t the divine image be found both in how we represent God and in how our higher capacities resemble him?,” I would want to say “Yes of course—both-and.” So I’m sorry if I gave the impression in the text that I thought any of the perspectives on the list provided are without value, but my introductory remarks in Chapter 12 were simply to point out that one brief chapter cannot discuss them all. And certainly there is a wonderful and unique sense in which Christ in his incarnation bears the image of God, as Keathley points out, and as I emphasize (pp. 285–86).

There is, however, one further point that is worth making here. Keathley rather implies that the substantive view provides a particularly strong perspective on the ontologically unique value of humanity made in the image of God as if, by implication, a more functional view does not. I think not. Quite the reverse, the kingly and priestly status bestowed upon humankind to be his earth-keepers is not only a valuable interpretation of the relevant biblical passages, but also acts as an important guard against a possible unfortunate implication of the substantive view. This is the idea that some aspect of an individual that may be severely lacking in some substantive list of human characteristics that are deemed crucial to the image of God idea might in some way make them of less value than people who have the full list. As Keathley points out: “Proponents of the substantive view have been hard pressed to identify what exactly about the human essence manifests the imago Dei.” This point is rather crucial in the context of genetic disabilities. As highlighted on page 290: “Humankind’s value lies not in some list of intrinsic qualities, but in God’s grace, in his bestowal of a kingly, priestly status that we certainly do not deserve”. This is an ontological reality—a status bestowed by God—and I think it is crucial in defending humanity against the never-ending sinful tendency to categorize certain human groups or individuals according to the particular characteristics that they do—or more often, do not—display. In an era when genetic enhancements of humanity are being proposed by Transhumanists on a regular basis, this point is of particular importance.

DICI and God’s Plan for Our Lives

I am pleased that Clay Carlson thinks that DICI can readily lend itself to a conversation with theology concerning the extent to which God determines our futures, and his use of blood cholesterol to illustrate the DICI concept is helpful. As far as the theology is concerned, the questions are many:But certainly a great topic and one for another time, perhaps. In the interim I thank Clay Carlson for his insights. Maybe he is the one who should write the book that this topic needs? What is the difference, if any, between divine providence and determinism? Are we like the more conservative Muslims (with whom I spent many years living in the Middle East) who speak about some future plan and then, at the same time, brush their forehead? Why do they do that? Because in folk Islam it is often said that God’s will is written on your forehead. So is divine providence written not upon our foreheads but in our genomes?

All these are great questions—and I am so glad that I specifically chose not to address them in Genes, Determinism and God! It was quite enough for a biologist to start diving into the philosophy of free will and the interpretations of imago Dei—already enough topics where angels fear to tread—but then to add on also a topic on which there is a vast theological literature, and on which strong opinions are held, often leading in diametrically opposite directions, was clearly biting off more than one could chew, quite apart from questions of space (as it was, I had to slice off thousands of words of an earlier draft of the book to fulfill my contractual obligations). But certainly a great topic and one for another time, perhaps. In the interim I thank Clay Carlson for his insights. Maybe he is the one who should write the book that this topic needs? And I am of course pleased that Carlson sees DICI as a “key acronym.” Jaw-breaking as it may seem, I do think it helps to refocus the conversation.

The Theological Ethics of Prenatal Diagnosis

Michael Wittmer raises some important questions concerning prenatal diagnosis and what we now call embryo editing in the light of the genetic mutations that lead to disease. Since writing the book, the use of CRISPR-Cas has galloped ahead at a great pace, leading to the infamous embryo editing of Chinese twins and the subsequent ethical outcry from the international scientific community. A further consequence has been the reported imprisonment of the lead researcher on the premature use of CRISPR-Cas in this way. A thorough update and further reflection on this field is clearly beyond the present scope of these brief comments. But for those interested I do touch on some of these issues further in a series of three lectures that I gave at New College, University of New South Wales, in September 2018.There are available online.

Freedom and LGBTQ

The biological literature on Same Sex Attraction [SSA] has advanced slowly since the writing of Genes, Determinism and God. Perhaps the most significant finding has been the description of a handful of genetic variants at a statisticallyThis is the main reason I left it out: speculation in the absence of data is unlikely to contribute anything useful to such a complex field. significant level that are associated with those who self-identify as experiencing SSA.Ganna et al., Science 365, August 2019. An updated account of the literature (up to the end of 2019) is provided in Are We Slaves to Our Genes?

Wittmer asks some interesting questions about SSA, such as whether people’s choices about unwanted SSA might lessen it either for themselves or in subsequent generations. A thorough search of the literature would be necessary to see if such questions have been addressed systematically, but I suspect not.

As far as the (reliable) genetic literature on transgenderism is concerned, it is tiny and has a long way to go before achieving the kind of reliability achieved by Ganna et al. This is the main reason I left it out: speculation in the absence of data is unlikely to contribute anything useful to such a complex field.


This conversation has, I think, demonstrated quite clearly that the study of genetics in general, together with its implications for differential human behaviors in particular, provides a wonderful opportunity for scientists, theologians, philosophers, and others to meet round the table and find mutually interesting things to talk about. As we note here, finding the right language to communicate clear concepts across disciplines is one of the main challenges. But this challenge is typical of the science-religion engagement more broadly. And long may such interactions continue!