Part 1: substance dualism and physicalism
Hylomorphic dualism
Hylomorphic dualism is a middle ground view between substance dualism and physicalism. This view is based in hylomorphism, the Aristotelian doctrine that corporeal substances are made up of matter (hylē) and form (morphē). Form is that which gives a substance its attributes (e.g., color, shape, size) and powers, while matter is what receives and individuates form. (Forms, such as dog-ness and triangularity, don’t exist by themselves – at least, not usually – they exist in individual substances, like dogs and triangles, which are distinguished by their unique parcels of matter.)
Hylomorphism was first proposed to help explain change. For change to really happen, there must be something that underlies and stays the same, and something that changes. If the former doesn’t exist, then nothing really changes, things just come into and go out of existence. (For example: if nothing underlies and persists through change, then a banana doesn’t change from green to yellow, instead a green banana goes out of existence and a yellow banana comes into existence.) If the latter doesn’t exist, then nothing ever changes at all.
When it comes to substantial change (change from one substance to another), the thing that underlies must be something that is not itself a substance, but can take on new attributes and powers (this is what Aristotle called “matter”), and there must be something in virtue of which the matter comes to have new attributes and powers (this is what Aristotle called “form”). Even hyper-reductionist physicalists should agree that substantial change occurs, since fundamental particles can decay into other kinds of fundamental particles. Thus, the existence of matter and form as metaphysical parts of substances is well-grounded in the fact that change (especially substantial change) really happens.
Hylomorphic dualism is just the application of hylomorphism to human persons. Like all other material substances, humans have both matter – which individuates us from other humans – and substantial form – which gives us the attributes and powers that are proper to humans. This includes not just attributes like shape and size, but also our perceptual and cognitive powers. Aristotle referred to the form of a living thing as its “soul” (psychē); not just for humans, but for other vegetative and sentient life as well. However, he argued that the human form/soul is unique because it has a rational intellect which is immaterial and naturally indestructible (De Anima 3.4-7).
This view avoids the problems that are associated with substance dualism and physicalism. Unlike substance dualism, hylomorphic dualism conceives of a human as a single substance comprising both body and mind. There is therefore no interaction problem, because the form of a person ‘interacts’ with her matter in the same way that form and matter ‘interact’ in any other material substance, namely, by informing its attributes and powers (both bodily and mental). There is also no problem of personal identity, because a person is an ontological whole rather than a mere aggregate of two distinct substances (her body and her mind). Likewise, the fact that our perception and cognition are fundamentally embodied poses no issue for hylomorphic dualism, because a person’s mind is integrated with her body as proper parts of one and the same substance.
Hylomorphic dualism can also sidestep the arguments against physicalism that I gave earlier. These arguments show that our cognitive processes can’t be wholly corporeal, since our concepts are inherently determinate and universal, whereas physical facts are indeterminate and particular. This also shows that our intellect isn’t wholly material in the Aristotelian sense, because our concepts can abstract away matter to get at the universal forms like triangularity. Hylomorphic dualists aren’t committed to saying that humans are wholly material; we can say, as Aristotle did, that the human form/soul has some operations that are immaterial.
By the scholastic principle agere sequitur esse (“action follows being”), the fact that the human substantial form has immaterial operations means that it also has an immaterial mode of subsistence. Since my intellect isn’t tied to or reducible to my body, unlike my other operations – for example, sight, which is tied to (at least) my eyes and the occipital lobe of my brain – it can exist even if my body does not. Indeed, as an immaterial thing, it’s not naturally destructible as material substances are. When I die, and my matter ceases to be informed by my substantial form, the immaterial operations of my substantial form that don’t inform any matter will continue to exist, and so my substantial form will still exist. And it will exist in an individualized way, distinguished from other human substantial forms by its unique causal history (having been combined with my matter).
However, my form will be an incomplete substance after my death. It won’t be me, because I am a composite substance made up of both matter and form. It won’t naturally undergo new perceptual experiences, because my perceptual abilities are tied to my body (see the arguments against substance dualism), and it won’t be able to form any new concepts, because new concepts are formed based on our experiences of the external world (even though concepts aren’t reducible to perception). And although this is controversial among hylomorphic dualists, I don’t think the post-mortem human form is naturally conscious, at least not apart from supernatural intervention. If syncope (temporary blood loss to the brain) results in a loss of consciousness, then the complete disconnection from the brain that comes with death should also result in a loss of consciousness, even though the human form persists through both these things.
In summary, based purely on philosophical considerations in the philosophy of mind, we can know that humans exist as a composite of body and form/soul, that the form/soul is partially immaterial, and that our form/soul persists after our death in an individuated but severely impaired way. How does this square with Scripture and our three axioms about the afterlife?
Hylomorphic dualism and Christian anthropology
According to Genesis 2:7, when God created the human, he first made a body out of dust and then breathed spirit/breath (Heb: ruach; Gk: pneuma) into it, and “the human became a living soul.” The body apart from the spirit is dead (Jas. 2:26), and at death, the body/dust returns to the earth and the spirit/breath returns to God (Ps. 104:29; 146:4; Ecc. 12:7; cf. Zech. 12:1; Acts 7:59). It appears that a person’s spirit continues to be individualized after her death, as evidenced by the little girl whose “spirit returned” when Jesus resurrected her (Lk. 8:54-55), and by the examples of Jesus (who gave up “his spirit”; Matt. 27:50; Lk. 23:46; John 19:30) and Stephen (who told Jesus to “receive my spirit”; Acts 7:59). A soul, on the other hand, can be killed (e.g., Num. 31:19; 35:11, 15, 30; Josh. 20:3, 9; Matt. 10:28; Mk. 3:4) and be dead (e.g., Lev. 21:11; Num. 6:6; 19:11, 13; Josh. 2:13; Jas. 5:20; Rev. 16:3).
These are the clearest passages that deal with the relationship between body, spirit, and soul. Based on this, it seems that the Aristotelian concept of the human ‘soul’ or substantial form actually corresponds to the Scriptural concept of spirit, as the principle that animates a person and continues to exist after a person’s death. The Scriptural concept of soul corresponds not to a person’s substantial form, but to the person herself, who is a composite of body and spirit and can die. Neither substance dualism nor physicalism correspond as well as hylomorphic dualism to the Scriptural data, since the Aristotelian categories of matter, form, and substance map almost one-to-one onto the Scriptural categories of body, spirit, and soul.
The centrality of bodily resurrection
But what about the three claims that nearly all Christians affirm about the afterlife? The first claim is that the bodily resurrection is our primary hope for life after death. This is well-grounded in Paul’s argument for the resurrection, in which he says that if there is no resurrection, “those who have died in Christ have perished... we are of all people most to be pitied” (1 Cor. 15:12-19). Paul says that the resurrection is the hope for those who grieve (1 Thess. 4:13-18), and that he doesn’t want to be “unclothed,” that is, bodiless (2 Cor. 5:3-4). In the New Testament, the resurrection is mentioned far more than any conscious intermediate state, if such a state is mentioned at all (the most likely prooftext for such a state is Luke 16:19-31, which is plausibly a parable).
Hylomorphic dualism provides a strong philosophical basis for this belief. My substantial form will continue to exist immaterially beyond my death, but in a severely impaired way, without new perceptual experiences and plausibly without any consciousness at all. This fact is reflected in the Hebrew Bible’s assertions that the dead cannot know or praise God (Ps. 6:4-5; 30:8-10; 88:9-12; 115:17; Isa. 38:17-19), and that their perception and cognition are at least severely impaired (Ps. 146:3-4; Ecc. 9:5-10). It’s also reflected in the metaphor of death as sleep, which is found all throughout the Scriptures. Sleep is an accurate metaphor for death in another way: if my form does undergo conscious experiences after death, they won’t be directly experienced by me, but I will remember them when I’m resurrected, like my memories of a dream when I wake up from sleep.
The only way for me to exist normally after death, and indeed for me to exist at all after death (since I am a composite of matter and form), is for my form to once again inform matter and become part of a material substance. This is just metaphysical language for bodily resurrection. Therefore, unlike substance dualism and physicalism, hylomorphic dualism provides both a motive and a mechanism for resurrection.
The immediacy of paradise
The second claim that nearly all Christians affirm about the afterlife is that some people will have immediate, paradisiacal existence after death. Can hylomorphic dualism explain this? Yes, and it follows the Non-Existence Thesis rather than the Intermediate State Thesis (see above). A person, who is the composite of her matter and form, doesn’t exist after her death. Her first conscious experience after death will be at the resurrection. Even if we assume (as I don’t) that her spirit has conscious experiences between death and resurrection, she won’t experience them, she’ll just remember them when she’s resurrected, analogously to how we can recall dreams after we wake from sleep. Therefore, from her perspective, she will immediately experience paradise after she dies.
The identity of the dead and resurrected person
The third claim, that the person who dies is numerically identical to the person who is resurrected, might be the hardest one to explain on a hylomorphic view. Since I affirm that the person (a composite of matter and form) ceases to exist between death and the resurrection, I also have to deny the widely accepted axiom No Gappy Existence: that one and the same thing can’t begin to exist more than once.
However, unlike physicalist Christians, hylomorphic dualists can deny NGE without any weird consequences about personal identity. Whereas physicalists say that a person just is identical to a certain physical process, hylomorphists say that a person is constituted by matter that’s informed by a particular substantial form. If a person ceases to exist, but her individual substantial form continues to exist, then that same person can come into existence again if her form once again begins to inform matter. Since the person isn’t annihilated, but corrupted (broken up) into matter and form, her particular form and matter can recombine to generate the same person. There’s no danger that two copies of the same person could exist if her body is duplicated, as in physicalism. That’s not even a metaphysical possibility, because a person is a single material substance with a particular substantial form.
In fact, hylomorphists already have good reason to deny NGE, even apart from any considerations about bodily resurrection (Toner 2015). When two or more substances combine to form one substance (for example, hydrogen and oxygen making water), the initial substances cease to exist actually, but exist virtually or potentially in the new substance, and can begin to exist actually again (so the same hydrogen and oxygen atoms can be recovered from an H2O molecule). Aristotle argues for this when he responds to a metaphysical argument against the possibility of combination:
For, according to some thinkers, it is impossible for one thing to be combined with another. They argue that (i) if both the ‘combined’ constituents persist unaltered, they are no more ‘combined’ now than they were before, but are in the same condition: while (ii) if one has been destroyed, the constituents have not been ‘combined’ – on the contrary, one constituent is and the other is not, whereas ‘combination’ demands uniformity of condition in them both: and on the same principle (iii) even if both the combining constituents have been destroyed as a result of their coalescence, they cannot ‘have been combined’ since they have no being at all. (De Gen. et Cor. 1.10)
This Parmenidean argument seeks to show that combination is impossible. You can’t really combine two things to get a third thing, because you’re either left with (1) the mere aggregate of two things, (2) one of the initial two things, or (3) the initial two things are annihilated and a third thing is created. Like Parmenides’ argument against the possibility of change, this argument relies on a stark distinction between existence and non-existence. You can’t have two things and a third thing that exist in the same way, at the same place, at the same time, so combination is impossible.
Aristotle rebuts this conclusion by saying that there’s something in between actual existence and non-existence, namely potential existence. When two substances are combined, they exist potentially in the new substance, which exists actually. But this means that NGE is wrong, because things can cease to exist actually and begin to exist actually again, as long as they have potential existence in between. Since I do exist potentially after my death, inasmuch as my individual form still exists and has the potential to combine with matter, hylomorphism can account for my personal identity at the resurrection.
Conclusion
The three claims of Christianity about the afterlife appear inconsistent, since the central importance of bodily resurrection seems to conflict with the immediacy of paradise after death. But from considerations in the philosophy of mind, independent of theological concerns about resurrection, we can determine that hylomorphic dualism is true, which makes bodily resurrection not only logically possible but plausible. There's a solid metaphysical basis to accept the Scriptural tripartite division of humans into body (matter), spirit (form), and soul (substance), as well as the survival of the spirit after death and the possibility of bodily resurrection. Our Christian hope for the afterlife is philosophically sound!
Appendix: survivalism vs. corruptionism
There’s a debate among hylomorphic dualists about whether a human person survives between death and resurrection (survivalism), or the human form between death and resurrection does not constitute a human person (corruptionism). I think corruptionism is pretty obviously true from a hylomorphist perspective, so I didn’t really discuss the debate above. Here, though, I’ll briefly explain why I think corruptionism is correct.
First, there’s an exegetical debate about whether Thomas Aquinas was a survivalist or a corruptionist. Since I don’t feel the need to agree with Aquinas on everything, I don’t think this has much bearing on whether or not corruptionism is true. But it’s worth noting that Aquinas was pretty clearly a corruptionist and not a survivalist. Early in his career, he talked explicitly about this topic, in his Commentary on the Sentences. Here, he rejected Plato’s substance dualism in favor of Aristotle’s hylomorphic dualism:
...the opinion of Aristotle, which all current [authors] follow, [is] that the soul is united to the body as form to matter. Hence the soul is a part of human nature, and not some nature per se. And since the notion of a part is contrary to the notion of a person, as was said, therefore the separated soul cannot be called a person, since even though it is not actually a part [when] separated, nevertheless it has the nature to be a part. (In Sent. III.5.3.2; transl. Nevitt 2016)
Likewise, in his commentary on Paul’s (1 Cor. 15) and Jesus’ (Mk. 12:24-27) arguments for the bodily resurrection, Aquinas insisted that these arguments depend on the separated spirit not being a person:
The soul of Abraham is not, strictly speaking, Abraham himself, but it is a part of him. The same goes for the others [i.e. Isaac and Jacob]. Hence the life of the soul of Abraham would not be sufficient for Abraham to be living, nor for the God of Abraham to be the God of the living; but [this] requires the life of the whole composite, namely of soul and body. (In Sent. IV.43.1.1; transl. Nevitt 2016)
Man naturally desires his own salvation. But the soul, since it is a part of the man, is not the whole man; and I am not my soul. Thus, even though the soul attains salvation in the afterlife, nevertheless I – or any man – do not. (Super 1 Cor. 15.2.924; transl. Reese 2024)
Aquinas also said in various places, up through his last writings, that Christ didn’t exist as a human person while he was dead, which implies that the separated human form by itself isn’t a person (Nevitt 2016). The standard survivalist response is that although the human form isn’t a person by itself, it does somehow constitute a person; but this would go against Aquinas’ insistence that we don’t attain salvation if our separated form does.
The metaphysical argument for corruptionism is also quite straightforward. The essence of a human, which is rational animality, includes both material (animality) and immaterial (rationality) aspects. If it only included immaterial aspects, then hylomorphic dualism would be no different than substance dualism, since our connection to our bodies would be only accidental. But nothing can exist without all the things that are essential to it; that’s what it means for something to be essential. Therefore, no human being can exist without both matter and form, and a person ceases to exist when her matter and form separate (Nevitt 2020). Yes, her form continues to subsist immaterially, but as its own incomplete, non-human substance, not as her.
Finally, on the theological side of the debate, survivalists consistently claim to have the upper hand. This is because most hylomorphic dualists are Catholics, who accept the doctrines of purgatory before resurrection and praying to the saints, which seem to require that people exist between death and the resurrection. I’m not a Catholic, so I don’t particularly care whether corruptionism is compatible with praying to the saints – although it’s worth noting that Aquinas believed it is (In Sent. III.22.1.1; ST II-II.83.11). In fact, I’m inclined to believe our separated spirits aren’t conscious at all, in light of various Scriptural passages that indicate that. The numerous places across Scripture where dead people are said to be “no more” also supports corruptionism over survivalism.
In my estimation, corruptionism has the upper hand over survivalism in terms of metaphysics, theology, and Thomistic exegesis. This means that death really is as serious as it appears (Reese 2024). It’s not just a gateway to heaven, it means that we cease to exist; death truly is the “last enemy” which will eventually be conquered by God (1 Cor. 15:26). Any other view would make bodily resurrection superfluous, since it would make the body merely accidental to human existence. This should make us even more grateful that God has provided a way for death to be defeated, namely resurrection in Christ!
