A recent article by New Scientist magazine entitled “How Science Takes the Bible to Bits” has proven to be, at times, an exercise in bad critical thinking.The author, Bob Holmes, is not entirely to blame as he was merely offering critique of Steven Jones’ The Serpent’s Promise that aims its petulant pages, as it were, directly at the Christian faith. Holmes notes that Jones tackles
“big topics such as the origins of the world and of humans, Noah’s flood and the other epic disasters, and the ultimate fate of Earth [while sketching] out our scientific knowledge of each.”
Considering Science’s inability to answer the origin of the world or humans (Big Bang’s first cause? Origin of the first cell?), it seems doubtful that Jones could offer anything substantial to the conversation by way of refutation. I did want to zoom in on something that Holmes mentioned with regard to one of Jones’ arguments in the book. He writes:
“To those who believe that humans are endowed with a soul from the moment of conception, he points out that his mother was an identical twin formed when a fertilised [sic] egg accidentally split into two separate embryos. What happened to the single soul when it found itself with two bodies? ‘Were my mother and her sister, my Aunt Pegi, blessed with just half a copy each,’ he asks…”
Unfortunately, Jones fails to understand the Christian view on souls. In his attempt to provide a reductio ad absurdum for soul endowment – “Were my mother and her sister, my Aunt Pegi, blessed with just half a copy each…” – Jones stumbles into a category error. His argument assumes that the soul is somehow affected by the material embryo and therefore trades on the notion that reductive naturalism is true; that is, only material properties exist like cells, molecules, atoms, etc. So, according to Jones’ reasoning, if somehow it was a physical property and if it manifests at the moment the sperm fertilizes the egg, then the single soul has split into two souls.
Jones does not seem to be aware that Christians are typically substance dualists; that is, they believe that, while the body has a material property, the soul has an immaterial property. As the apostle Paul writes,
“we are of good courage, I say, and prefer rather to be absent from the body and to be at home with the Lord” 2 Cor 5:8.
In other words our soul, while in a particular relationship with our bodies, is not identical to it such that it can separate from our body after death and be in the presence of God. Now, there are some excellent philosophical arguments that prove the body/brain is not the same as the mind/soul, however that particular enterprise is for a separate discussion. Anyone interested can begin with “What It Is Like to Be a Bat” by Thomas Nagel that investigates the subjective character of experience. All this post is concerned with is whether or not Jones has sufficiently addressed the Christian view. He has not. What he tries to do is pose a problem with a physical substance (two embryos out of one sperm and one egg) in order to disprove an immaterial substance – two separate categories altogether.
The fact is Christians are divided over when, specifically, ensoulment occurs. But even those who believe it occurs at conception do not suffer from Jones’ problem of twinning. Perhaps twinning is genetically predetermined in which case ensoulment could be predetermined as well. Perhaps twinning is determined by the fertilization event asymmetrically, i.e. one embryo generates another, in which case the second generated embryo would be ensouled when it is generated. As I said neither of these scenarios is a problem for the Christian view, for since God determines ensoulment, then in the case of twinning,
“[which] results in a multiplication of human embryos… God gives new souls appropriately.”
 David Albert Jones, The Soul of the Embryo: An Enquiry into the Status of the Human Embryo in the Christian Tradition (New York: Continuum, 2005), 227.