The Case for Immortality
In spite of the fact that it had long been considered a bona fidephilosophical topic, we have in recent times without fanfare written the question of immortality off as a religious matter not deign for rational scrutiny. This may be on account of its association with the human soul, which has lost its philosophical reputation in modern times in the eyes of many.
Nonetheless, it is puzzling how we have shuffled the whole question away without so much as a refutation, at least of the best case that can be made for it. Part of the problem may be that soul theory had long been divided into two distinct and non-collaborative camps, the dualist and the non-dualist. Dualist theory hasits ancient roots in Plato (42?- 348/347 BCE) and its modern ones in Descartes (1596-1650), whereas non-dualist theory has its roots in Aristotle (384-322), with a medieval boost from Thomas Aquinas (1225-1274). Platonic dualism seemed to give us a straighter shot at immortality, but at the cost of accepting a non-realist or idealist account of the physical world, which Plato saw as a sort of limbo between existence and non-existence. His immortality argument, which we will get to shortly, may have merit, but only if we can somehow dissociate it from his untenable view of matter and bodily existence. Aristotle, Plato’s student, did much to address what he took to be the flaws of Plato’s philosophy, developing in the process a non-dualist theory of soul which delightfully takes matter and bodies seriously. But it came with an apparent denial of the possibility of the immortality of the soul. Thomas Aquinas later deftly noticed that Aristotle’s discussion of human rationality – a discussion prescinding from questions about soul, which Aristotle took to be a matter for biology – might leave us with a way of making an Aristotelian case for immortality of the human soul in particular. Finally, the dualist theory of René Descartes accepts the soul narrowly as a rational principle, while writing off the body as a “machine of nature” not even counting as substantial, but rather as part of the singular substance of extended matter.
Perhaps soul theory fell out of favor because of the mutually denigrating impact these three traditions had upon one another. Aristotle’s theory probably supplanted Platonic notions in the late medieval era due to the emerging recognition of the latter’s incompatibility with Christian doctrine, which demands a robustly realist vision of the body and physicality. Moreover, there is reason to believe Aristotle’s soul theory was dropped during the Renaissance when his Physics justifiably fell out of favor. Descartes’ theory alone was left in their wake as the going trend, but it was attached to the heavy baggage of modern rationalism. The eventual turn toward empiricism seems to have cast a dark shadow over Cartesian soul theory, hence, as its only then current representative, on soul theory in general.
What I propose is to reconstruct an updated case for immortality using both Platonic and Aristotelian traditions collaboratively. The structure of the argument will be as follows.
1. Establish by a non-dualist (Aristotelian) rationale that living things have souls, i.e. existent non-physical organizing principles of the body.
2. Make the Platonic case that if non-physical things exist, they do not die or decompose, hence are immortal.
3. Confront the non-dualist challenge against the immortality of the soul in spite of Plato’s argument.
4. Explore the Thomistic/Aristotelian proposal that rational thought is an activity “not pertaining to the body”.
5. Make a stronger case for immortality based on the independent agency of rational thought.
When considering whether souls exist, the question arises whether to take a dualist or non-dualist approach. I argue we ought to take a non-dualist approach on the grounds that dualism –whether Platonic or Cartesian – discredits itself by not taking the body seriously enough. Platonic dualism fails to take the body seriously by failing to take material existence seriously. Cartesian dualism’s problem, on the other hand, is its failure to take organismic existence seriously.
For Plato, the body is little more than a shadowy, half-real prison for the soul. Our identity is entirely with the soul, and our happiness secured only in its separation from the body.
For Descartes, on the other hand, the human body is a machine of nature made by God to house the human soul. The relationship between the two is mechanical and accidental. Descartes even conceded that it would be possible for a human body to exist on its own, but that God would not let that happen. As for all other forms of life, they are soulless, and their existence is purely mechanical. In short, the only thing the Cartesian soul accounts for is rational thought.
These two views of soul are untenable, among other reasons, because they gain ground for soul only by denying of the body things we typically grant to it as obvious: material and organismic existence.
The non-dualist approach begins by conceding that there are some basic things we notice about bodies, i.e. physical living things. First, we notice they have unity at any one time. Secondly, we notice they have identity over the course of time and complete turnover of matter. Now, anything that as unity and identity in this sense must have a principle existing within it to account for those properties, without which we should have to concede that they lack those properties. For example, the house that I am in has an identity to it which is conferred by the matter of which it is made. This is a physical principle of identity. Unless I have been hoodwinked, in which case the identity of my house is only by social or functional convention, most of the materials that were put in place in a certain manner when this house was built are still present in the current structure, allowing me to say the house is physically the same house as when it was built. Of course, I speak loosely, since changes have been made over the years. Nonetheless, a certain physical core has remained unchanged, in virtue of which and to which extent it is the case that this is the same house that was built on this lot years ago. That is the way it goes for physical principles of identity.
Now, granted that a living thing has identity over complete physical change, to what principle within it can we ascribe it? By logical necessity, it would be either a physical or non-physical principle. But it could not be a physical principle, since a living thing turns over its matter completely without loss of identity. Hence, its principle of identity could only be non-physical, which is what a soul is: a non-physical organizing principle of the body.
We obtain something similar regarding the unity of living things. At any one time, the body is one, even though it is made up of many parts. It is not just an aggregate, the way my house, though accidentally organized, is an aggregate. A body, for example, is not just a confederation of cells. If I insisted it were, then that same reasoning would compel me to insist that each cell, in turn, is but a confederation of its parts, and so on down to elementary particles. The result would force me to regard bodies as vast clouds of accidentally arranged particles, a total denial of how we actually do life science. Shall we say life science is just a convenient deception allowing us to inventively project unities onto scattered manifolds for our own academic and practical convenience? Or shall we rather, as I urge, just notice organisms as we find them, i.e. as unities ?
The implications of this latter, far more reasonable choice, is that living things have non-physical organizing principles of unity, i.e. souls.
Plato, in my estimation, never had an argument for the existence of souls as rigorous as what Aristotle later produced, and which we have just discussed. But interestingly enough, he had an argument for immortality not easily dismissed. The argument applies to all existing non-physical things and goes like this (From the Phaedo):
1. Experience gives us only reason to believe that physical things die, for they die by corruption or decomposition of the body.
2. If 1, then 2a. we have no reason to believe that existing non-physical things die.
3. If 2a. then we have good reason to believe that existing non-physical things are immortal.
4. Souls are non-physical things.
C. If souls exist, we have good reason to believe they are immortal.
Putting together this Platonic case for immortality with Aristotle’s case for the existence of souls, it would seem that we have at least the fixings of a case for immortality. But we are not out of the woods yet.
To be sure, Aristotle’s argument for soul makes a respectable case for the soul’s existence – that is, for every living thing having a soul. This is quite different from dualist cases that focus only on the human soul. Here, we have also the souls of amoebas to contend with.
Bear in mind that Aristotle’s soul theory was developed in the context of biological studies generically. Of course, he was aware of Plato’s immortality argument, but denied its application to souls as he conceived them, on the grounds that his theory allows for another way – besides decomposition - for souls to cease existing: the simple cessation of activity. As Aristotle saw it, unlike physical things, which exercise their existence by occupying space, the existence of non-physical things can only be by the exercise of an activity appropriate to them. Now, the souls of living things exist by exercising the activity of organizing matter into bodies. But when the body dies, this activity ceases. Hence, it should follow that the soul also ceases to exist. After all, what could the soul of an amoeba conceivably be doing without having any matter to organize into a body?
At best what we have here is a stalemate, with Plato’s argument capable of denying the death of souls, but Aristotle’s challenge denying them activity. We might be able to squeak out some seminal notion of immortality of souls, but certainly not immortality in any active sense.
In spite of all the above, it happened more than a millennium later that Thomas Aquinas, a loyal Aristotelian disciple of Albert the Great, found a possible avenue for a successful immortality argument in Aristotle’s own work. That it was not noticed by Aristotle himself may be due to the way he compartmentalized his work, with soul theory belonging to biology and not to anthropology specifically. The observation Aquinas made was that Aristotle, in speaking of human thought, noticing that humans were both animal and rational, remarked that human rationality does not pertain to the body, whereas human animal awareness does pertain to the body. To Aquinas, this signified the possibility that one could, according to Aristotle’s own thinking – albeit he may not have ever thought this out – ascribe to the human soul an activity independent of the body. If so, this would give us room to make an exception for human souls, arguing they might yet be immortal because, even after the death of the body, they would still have an activity to exercise, that is, rational thought.
This leaves us to ask some important question about ourselves. First of all, do we have genuine mental agency? In other words, does the human mind amount to more than simply all that which supervenes upon human brain activity? If we decide that humans do have genuine mental agency, this would establish what can be called mental autonomy: that the mind is more than merely the result of bodily functions (including brain activity). If so, does our coming this far give us cause to press even further to affirm active mental independence of some kind, however pockmarked by the absence of instrumental access to the brain? This would be the basis of a contemporary case for immortality.
I think experience gives us a strong case for mental autonomy. Clearly, the causal interactions between brain activity and mental activity go both ways. In addition, just as there are many brain activities original to the brain and not derived from mental influence, so, too, there are mental initiatives that would seem preposterous to ascribe to occult origins in physical processes in the brain. My decision to write this paper, for example, could not reasonably be thought of as having been initiated in and ultimately determined by physical processes in the brain. Even to try to imagine this involves overt category confusion.
Whether or not mental autonomy implies some kind of mental independence is a tougher question. We can look for the answer empirically in the study of stroke and coma victims, etc. But without philosophical grounding, these efforts alone will remain non-starters. If we take Aristotle’s notion of soul seriously, however, seeing souls as the principle that causes the body to be the body in the first place, this would give soul primacy over the body, getting us closer to a thesis of independence. Aristotle’s own insistence that body and soul begin their existence at the same moment allows for no pre-existence of the soul and thus makes it difficult for us to make any major inferences from the primacy of soul over body to potential continued existence of the soul after the death of the body. Nonetheless, a distinct imaginable possibility is there.