Much theology presupposes a metaphysical spirit or soul, the existence of which has been questioned in contemporary neurobiological research. Green, Murphy and others argue for alternatives to metaphysical description. If the neuroscience is correct and the soul, if it exists, is not metaphysical then many theological descriptions will need serious revision or possibly even abandonment. One such theological description, directly affected and long considered to be an essential part of Christianity, is God's personal self-communication to humans. This has traditionally been understood to occur through the metaphysical human soul or spirit. The question explored in this article is whether the existence of a metaphysical soul is an all or nothing matter for Christian theology.
A rational and strong challenge to the existence of metaphysical soul is demonstrably not new. Nonetheless, from the beginnings of modernity it has been generally assumed, utilising Augustinian anthropology, that the soul was a metaphysical element of human anatomy. Huxley's work on sensation, including ‘Has the Frog a Soul’, determines the anatomical location of the soul by its supposed function. Huxley questions early modernity's assumptions regarding the nature of sensation and the presumed role of the metaphysical soul within the sensorium. Huxley deduces limits and conditions on the existence of the soul and arrives at a description which has similarities to Tertullian's corporeal description of the soul. Huxley, however, does not engage with Tertullian, whose relatively orthodox description of the soul answers a number of issues that Huxley raises. Tertullian's careful revision of the Aristotelian category of corporeality is not exactly the same as Huxley's nineteenth-century materialism or contemporary physicalism. Tertullian's description of the soul is remarkably similar to Augustine's, differing mainly on the issue of corporeality and metaphysicality. Tertullian's description ironically draws on and shares the same functions as Greek philosophy and medicine. This description of the soul seems to be based more on these sources than scripture, unusually for Tertullian. Some form of reappropriation of Tertullian's non-metaphysical soul may be useful in the contemporary debate, noting the limitations of his understandings of biology and physics. It seems possible to take note, in some form, of changed and better contemporary worldviews, in order to better describe theological anthropology and in particular that element related to the soul.