What do the Hebrew Bible (Christian Old Testament) and Christian New Testament have to say about the truth of substance dualism? Much ink has been spilt in addressing this question, but plausibly the answer one gives to it in part reflects what one believes about the purpose for which scripture is written. In what follows, it is assumed that the Bible is not a philosophy text that was written to address metaphysical questions like, ‘What is the nature of a human being?’, ‘Does the soul exist?’, or ‘Is physicalism true?’, but was authored for the most part as a narrative about the history of the people of Israel.
It would, however, be a mistake to conclude that the Bible, because it is not a philosophical text that is written to address the nature of a human being, says nothing about that nature. In light of the scriptural evidence cited in the next section in which souls are considered to exist separately from bodies or to be re-embodied, it is reasonable to maintain the Bible simply assumes/presupposes the truth of substance dualism because substance dualism is the view that people naturally believe (Cooper 2000; Farris 2020: 21–23).
1.2.1 Scriptural support for soul-body dualism
A variety of biblical texts confirms the view that scripture presupposes the natural belief in substance dualism. For example, there is evidence of belief in ghosts of the dead found both in the Hebrew Bible and Christian New Testament. When Saul saw the army of the Philistines, he was afraid and consulted the Witch of Endor whom he asked to bring up from the dead the ghost of the prophet Samuel (1 Sam 28). Saul’s action was in direct violation of the Israelite law not to consult mediums or wizards (Lev 19:31; 20:6; Deut 18:10, 11), a prohibition which on the face of it presupposes the existence of the soul after physical death.
When the disciples of Jesus saw him walking on the sea, they believed they were seeing a ghost (Matt 14:26). In a passage about Jesus’ identity, he asked his disciples ‘Who do people say that I am?’, and he received the response that some thought he was John the Baptist, others believed he was Elijah, while still others thought he was Jeremiah or one of the prophets (Matt 16:13–14). Even Herod, who had John the Baptist beheaded, wondered if Jesus was John (Matt 14:2). The mere suggestion that Jesus might be John the Baptist is interesting because it is reasonable to think the location of John’s body was well known, and it could easily have been verified that his body was still there. What, then, were people, including Herod, thinking? Most plausibly, they thought Jesus was John’s soul re-embodied. The belief of ordinary people in substance dualism also provides the most plausible epistemological backdrop for the conviction of those who knew Jesus that he was casting out unclean spirits from people who were possessed by them (Mark 1:34). And when Jesus stood among his disciples after his resurrection, they were startled and frightened, and supposed they saw a spirit (Luke 24:36–37). As the New Testament scholar Joel B. Green, who rejects substance dualism, writes, ‘It is difficult not to see in the disciples’ responses a [substance] dualist anthropology; accordingly, in their imaginative categories, they were encountering a disembodied spirit, a phantasm’ (Green 2004: 91). Additionally, when Peter arrived at the door of Mary’s house after he had been jailed by Herod, the persons present insisted to a maid, Rhoda, who reported that Peter was at the door, that it could not be Peter but must be his angel (Acts 12:15).
And what about the apostle Paul? A comment of his in his second letter to the Corinthians indicates that he believed in substance dualism. In 2 Cor 12:2–4, he wrote,
I know a person in Christ who fourteen years ago was caught up to the third heaven – whether in the body or out of the body I do not know; God knows. And I know that such a person – whether in the body or out of the body I do not know; God knows – was caught up into Paradise and heard things that are not to be told, that no mortal is permitted to repeat.
The fact that Paul is uncertain about whether this experience was or was not ‘in the body’ makes clear that he believed it was coherent to think that he might have been caught up to the third heaven in a disembodied state (‘out of the body’), which suggests he believed in the existence of the soul and substance dualism. The fact that Paul believed this is not surprising, for two reasons. First, he was largely writing to ordinary human beings, and ordinary human beings believe in substance dualism. Second, Paul was a Pharisee, and as will be made clear below, the Pharisees believed in both the soul’s existence and substance dualism.
The philosopher Kevin Corcoran, who is not a substance dualist, concedes that biblical passages like those cited in the previous two paragraphs support the view that a person is distinct from its body. However, he writes that
to the extent that [such passages] suggest that a person might exist ‘apart from the body,’ it does not follow that the nature of that existence is immaterial or nonbodily […] So, to exist in a state that is ‘away’ from the body does not entail that the state is an immaterial state of an immaterial soul. It could be a bodily state that includes none of the matter that makes up the earthly body. (Corcoran 2006: 145–146)
It would be unreasonable to claim that these texts provide an account of the ontological nature of a self which exists or is capable of existing apart from its physical human body. However, it is reasonable to believe that they presuppose the truth of substance dualism in the broad sense that there are two substances, a physical human body and the self whose body it is, and that the latter is separable from and can exist apart from the former. What a philosopher does is reflect on the natures of the two substances. It is as a result of such reflection that features of the soul, like its simplicity as a substance and complexity in terms of its psychological capacities, are affirmed. But it must be emphasized that while such philosophical reflection enriches our conception of the soul which people like Jesus’ disciples, Herod, and Paul believed is distinct from and can exist apart from a human body or be re-embodied in a different human body, belief in substance dualism is not itself a result of philosophical reflection. The ordinary person naturally believes substance dualism. Thus, it is not surprising to read Corcoran’s recounting of how his mother, upon the death of his father when Corcoran was four, told him that his father was ‘now with God in heaven […M]y mother believed what most Christians have believed down through the centuries, namely, that we human persons are immaterial souls’ (Corcoran 2006: 11, original emphasis).
Anyone who is the least bit familiar with biblical studies will be aware that Christian theologians/philosophers have for two millennia been influenced by the substance-dualist thought of the Greek philosopher Plato (and Platonists more generally). Critics of substance dualism who are also Christians often allege that these theologians/philosophers erroneously read Plato’s ‘Greek’ treatment of substance dualism into the Bible (see Goetz and Taliaferro 2011: Chapter 1 for a detailed description of Plato’s view of the soul, which includes the claims that the soul is immortal [it never came into and will never go out of existence], uncreated, and will, if all goes well for it, survive death forever disembodied). These critics apparently believe that, had these theologians/philosophers not read Plato, they (the theologians/philosophers) would not have found a belief in substance dualism in the Bible, as if to suggest that Plato was the first person to come up with the idea of substance dualism. For example, the theologian Alister McGrath writes that ‘[t]he notion of an immaterial soul was a secular Greek concept, not a biblical notion […] The biblical vision of humanity was that of a single entity, an inseparable psychosomatic unit with many facets or aspects’ (McGrath 2015: 137–138). The New Testament scholar Joel B. Green writes about the post-resurrection appearance of Jesus to his disciples (Luke 24: 36–37) mentioned above that ‘we find no witness to resurrection as escape from bodily existence (as one would expect if a Platonic dualism were presumed here)’ (Green 2004: 92). Green goes on to claim that ‘Jesus [is not] an “immortal soul” free from bodily existence’ and that ‘[r]esurrection is not soul-flight’ (Green 2004: 92, 93). Green’s statements reflect his purpose of showing
that […] an anthropology that posits an ontologically distinct soul, which constitutes the ‘real person’ and which guarantees survival of personal identity from this life to the next, is not only unnecessary but actually stands in tension with key aspects of the resurrection message of the Scriptures. (Green 2004: 86)
Green seemingly believes that, because Jesus possessed a resurrection body, as opposed to being disembodied after death, he (Jesus) was not a soul and substance dualism is false. However, substance dualism per se implies nothing about whether the afterlife will be an embodied (as Christians believe) or disembodied (as Plato thought) existence. Substance dualism is no more, but no less, than the anthropological view that there is a soul which is ontologically distinct from its body, and this view can be true whether the soul is or is not embodied in the afterlife (or is or is not immortal or uncreated). In other words, substance dualism is not, as Green (and McGrath) seems to think, synonymous with Platonic substance dualism. One can believe in the former without believing in the latter. Those concerned about the influence of Platonic dualism on Christian thought seemingly overlook or forget the distinction between an ordinary belief in substance dualism and a philosophical development/treatment of that belief. Because a belief in substance dualism is commonsensical it is found at all points in time and space on the planet earth (e.g. it is found in Hinduism and Buddhism). While Plato philosophized about substance dualism, he did not come up with the idea. Therefore, if one rejects certain aspects of Platonic thought about the soul, one does not undermine the truth of substance dualism per se or the integrity of the biblical authors’ presupposition of it.
N. T. Wright is another biblical scholar who questions the belief in substance dualism in the New Testament (Wright 2016). He emphasizes that the New Testament does not concern itself with philosophical anthropology, and argues that when the New Testament authors do talk about the soul (psyche), it is not as an entity that is distinct from its physical body but as something like the Hebrew nephesh, which he believes is the living, breathing, creature with bodily and psychological properties (the view frequently referred to as Hebrew monism and a version of property dualism, for which see section 3.1). Wright claims that many Christians are unaware of this Hebrew anthropology because they have been influenced, if not blinded, by Greek substance dualism, particularly in its Platonic form where the soul exists disembodied forever after death.
What might a substance dualist say in response to Wright? First, it does not follow from the fact that the New Testament does not concern itself with philosophical anthropology that its authors, who were for the most part Jewish, embraced a Hebrew monistic view of a human being. The Hebrew Bible is no more concerned with philosophical anthropology than is the New Testament. To maintain that it teaches, presupposes, or implies a monistic understanding of a human being runs up against the fact that ordinary people, whether Jewish or non-Jewish, are substance dualists. We get a glimpse of the belief in substance dualism in 1 Samuel 28, which was cited above. Moreover, as Wright himself points out,
[a]ny Jew who believed in resurrection, from Daniel to the Pharisees and beyond, naturally believed in an intermediate state in which some kind of personal identity was guaranteed between physical death and the physical re-embodiment of resurrection. (Wright 2003: 164; cf. Cooper 2000: 101–103)
And as Wright points out elsewhere, one must be careful about using linguistic expressions as the basis for asserting what people believe about the nature of the afterlife. Wright makes clear that just as it is possible to use language about the soul and life after death to refer to the idea of physical resurrection, so also it is possible to use language about physical resurrection to refer to the idea of the soul and life after death. Thus, it is erroneous to conclude from the fact that the Pharisees are consistently described in the Gospels and the Acts of the Apostles and extra-biblical sources as believing in the resurrection of the dead that they did not believe in the existence of the soul that would receive a new body in the future. They did believe in the soul’s existence and its future re-embodiment, as Wright himself notes with the support of various texts (Wright 1992: 320–34).
Second, it should not be forgotten that the apostle Paul was a Pharisee. That he believed, like other Pharisees, in the possibility of disembodiment is evidenced in 2 Cor 12:1–4, which was cited above. Wright says the following about this passage:
[Paul] never suggests that, if he wasn’t embodied, it was his psyche which made the journey [to the third heaven]. The fact that he is uncertain about whether this experience was or wasn’t ‘in the body’ indicates that, for him, it wouldn’t have been problematic if the body had been involved. For him, the body could just as well have been carried up to heaven […] Equally, of course, that fact that he can consider the possibility that the experience might not have been ‘in the body’ does indeed indicate that he can contemplate non-bodily experiences, but […] I don’t think one can straightforwardly argue from this to what is now meant, in philosophical circles, by ‘dualism’. (Wright 2016: 6–7, original emphasis)
A substance dualist will likely respond that one need not argue from this passage to substance dualism. The fact that Paul can ‘indeed contemplate non-bodily experiences’, experiences had without a body, indicates that he presupposes commonsensical substance dualism. Wright seems to believe that the ‘dualism’ of philosophical circles is Platonic in form. One certainly cannot, as Wright says, straightforwardly argue from what Paul says in 2 Cor 12:1–4 to the conclusion that he believed in Platonic dualism. But, again, substance dualism and Platonic dualism are not the same thing. The latter is a species of the former, and a rejection of the species is not sufficient for a rejection of the genus.
The criticisms of biblical scholars and theologians of substance dualism examined in this sub-section reflect a belief held by many professional philosophers and scientists that substance dualism is false. The explanations given for this belief are typically that developments in neuroscience and the methodology of science as a whole support the falsity of substance dualism (see Theology and Neuroscience). Section 2 is concerned with these issues.