# Plato on Immortality 2

Updated on June 8, 2014

## A Proof of Immortality in Plato's Republic

Although most of Plato's proofs of immortality are in the dialogue named Phaedo, there are a few others, one of which appears in the last book of the dialogue Republic. This proof does not try to establish that an immortal soul exists but that, if it exists, a soul cannot be destroyed.

It is not likely that any immortality proof can be persuasive, although we don't have a priori grounds for excluding that some such proofs might be better than others. How does one assess proofs? We must have proofs which the ideal rational agent would accept if we are to be persuaded about any claims that can, on logical grounds, be true and can be false (though not at the same time, of course.) Yet, few people study logic is the discipline addressing issues of proof evaluation. Arguments come in two types (possibly in three, but the two are the basic types.) An argument can be deductive - in which case, the truth of the premises of the argument guarantees the truth of the conclusion; or, an argument can be inductive - in which case, the truth of the premises in an argument of this kind deemed strong does not guarantee the truth of the conclusion but establishes a sufficiently high probability that the conclusion is true. Deductive arguments depend for their "correctness" on the pattern/structure/form they have, with forms being either valid or invalid. We cannot rely on our intuitions to discern whether an argument form is valid or invalid. Plato himself often lays down invalid arguments in his dialogues - and you would be shocked how many reputable works, even academic books, harbor invalid arguments. If a deductive argument is valid, then it has passed the validity test. But it might still have premises that need not be accepted as true; in that case, the argument, although valid, is unsound; it is not an argument that the ideal reasoner should accept. When it comes to inductive arguments, we don't have structures or forms to study. The study of inductive arguments cannot be treated systematically but, fortunately, there are characteristic types of fallacies that afflict inductive reasoning. Such fallacies are to be found virtually everywhere you turn, if you know how to detect them. A principle of logical charrity requires that we the opponent to be making the most successful argument: thus, if we can attribute to the opponent a valid and sound argument, we must do this. If not, we may as well take the opponent to be making an inductive argument and assess whether the argument is free of informal fallacy and sufficiently or acceptably strong (although we don't have specific formal guideposts as to how to measure inductive agument strength; we can do better when it comes to comparing relative strengths of inductive arguments with, for instance, an argument that concludes that "all ducks are white" on the premise that 1,000,000 ducks have been observed as white is stronger than an argument that reaches the same conclusion on the basis that 1,000 ducks have been observed to be white.

Plato has an affinity for deductive arguments. Some of his arguments are invalid and even more are unsound. This is not as shocking if you consider that scholars today succumb to this logical malady. Logic is not taught widely and is not required in college!

We are ready to proceed with Plato's proof but, first, we need to mention a few things about the dialogue Republic, where this proof appears.

See results

## Plato's Republic

Like most Platonic dialogues, the Republic touches on many subjects but its foreground topic is justice. An organic theory of justice is defended, according to which the just state of affairs is attained when everything performs properly its natural function. It is assumed that nature, the totality of things, is objectively meaningful and accessible to the mind. Insofar as human beings have minds, they partake of the highest thing there is in the totality of things - because the most dignified entity is that which reflects the universe back to itself and understanding does precisely this insofar as the universe itself is meaningful. Yet, the human life we experience is sensed by a mind trapped in the body. Plato thought that empirical evidence establishes clearly that the vast majority of human beings are weighed down by their bodily sensations, desires, pleasures and the resulting hedonism and ignorance to an extent that they are barely human anymore. The highest goods are the goods of the mind and such goods are not subject to the law of diminishing returns: too much of them does not satiate; the pleasure from intellectual goods remains unabated even if more and more of them is added. The inferior, bodily indebted human beings who vie for vulgar satisfactions and for power are responsible for the sorry state of affairs we find in the world. Never is a properly good and just regime to be found. Plato, famously, asserts in this dialogue that the ills we find in the world of societies, conflict, and political competition can only cease if "philosophers" were to become rulers - or, less likely, if those who are in fact rulers were to become "philosophers." The term "philosopher" means one in whom the mind rules over the body and the source of highest pleasures originates in the things of the mind. Like a mathematician who will not care for the prize money once she has solved a problem - the money or the fame being decidedly inferior and insignificant next to the pleasure inherent in solving the mathematical problem - philosophers cannot be corrupted by material goods like money and power. Excellent natures can indeed become corrupted but only if their education is deficient. A corollary to this is that our venal rulers are not properly educated. The Republic is as much a dialogue on education as it is on justice because of this deep connection between the two. When, and only when, the "philosophers" rule we can have a system in which everyone's good can be served. This is because playing with the goods of the mind does not generate zero-sum games - which is the case with the material goods: when you solve a mathematical problem before I do, my material, competitive, venal, wishful or lower self is jealous; but as a "mathematician" myself, if I am really one, I rejoice at the solution of the problem. This is supreme bliss and it is not diminished by being shared! If, however, I vie with you with respect to money or power, it is only proper, and inevitable, that your gain is my loss. My envy directed at you is not a lapse into a lower part of my essence; it is only the appropriate reaction for this game of lower impulses. For as long as such types rule, and are ruled, there can be no escape from the cycle of social violence and economic injustice. Politics, by its very existence, reflects this. In the regime of the philosophers, on the other hand, it is those who despise politics that rule; only then can the ruled themselves be properly cared for - like when the cowherd can properly take care of the cows when she does not look how to goad or exploit them to make money but only when she has the proper knowledge of what is good for the cows themselves.

To rule the inferior masses, however, the philosophers will have to use propaganda and dispense lower pleasures: those who can do no better than make money, for instance, could keep their money but the philosopher-rulers should be aloof. Whether this is a feasible regime or not Plato will not make clear. Nor can Plato dispel the fear that such a system, even if attained, would not last for long. Plato thought that the foundation of this disinction between higher, philosophic, natures and the lower ones is in nature. This is not absurd because Plato takes the totality of things to comprise both material and immaterial things. Thinking in terms of how animals are bred, Plato wants the philosopher-rulers of the utopian regime to interbreed but he fears that something would go wrong along those lines.

One of the unfulfilled promises of the dialogue is to show that virtue or moral excellence is worthy of being chosen by the rational agent over everything else. It is difficult for us to grasp this but "virtue" includes not only what we may recognize as moral excellence but also intellectual talents. Insofar as intellectual pursuits are the highest goods, they ought to be worthy of being chosen absolutely - not for anything else they might make possible. If not, then whatever it is those talents make possible would be higher, thus contradicting the assertion that the intellectual talents are themselves the highest thing. The promise that the highest pleasure goes along with the highest goods seems to suggest that the goods themselves might not be the highest thing after all. Socrates is asked, in the dialogue, to prove that someone should still choose excellence even if he were to suffer enormously for its sake and were never to gain anything on account of this choice. Although Socrates embarks on the task, he ends up defending virtue or excellence not only for its own intrinsic value but also on account of the good things - higher pleasures - excellence makes possible.

In the course of this defense, an additional step is taken, which seems to further dilute the claims of excellence to absolute choiceworthiness. The person is said to be an immaterial entity, a soul, that cannot be destroyed but may be reincarnated serially. To be withdrawn from the murk of abortive reincarnations, in which one suffers the sickness, ignorance and frustrations inherited through the body, one may aspite to virtue. We are given more and more chances over multiple reincarnations - except, perhaps, for some who, Socrates says, are "incurable." The analogy here is between excellence-mind and health with the malady of the body being held responsible for the ills that beset us - with the bodily ills, too readily recognizable as illnesses, and the ills of the soul-mind being the moral vices themselves. These are the ingredients of the immortality proof we examine below. Once again, the praise of excellence, like the praise of health, does not stop at extolling the intrinsic value of the thing but also takes into consideration the goods that become possible exclusively by possessing virtue. It is possible that Plato does not see a dichotomy here - either something is good in itself, or it is good through its consequences. Indeed, Socrates asserts that the highest things fulfill both clauses. Popular religions today also promise and threaten with consequences to promote moral conduct.

The dialogue has a direct proof of immortality, in the Xth book, which utilizes the ingredients we outlined above. This proof does not have an existential conclusion - that immortal entities, which are presumably us as persons, exist. The conclusion is that the soul, given that it exists, is imperishable or immortal. We now turn to that proof.

## Plato's Proof of Immortality in the Republic

The proof requires a principle, which sounds, at first, rather implausible: Anything that can be destroyed at all, can only be destroyed by a deficiency (an "ill") that is (oikeion) intrinsic to it. Spelled out in first-order logic: "for any x, if x is destructible, there has to be a y such that y is related to x in such a way that y is the intrinsic deficiency for (that can destoy) x. The converse implication is plausibly intended: for any x, if there is a y such that y is the intrinsic deficiency that can destroy x, then x is destructible. It seems then that the two - destructibility and existence of an intrinsic deficiency - are related by the "if and only if" relationship. Usually we find this relationship in definitions. Plato's view of definitions is rather narrow: he takes definitions to be statements attesting to discoveries about how things work in reality (with reality comprising a transcendental realm of Forms.) It is not important if the principle we are considering here is intended as a definition or as a metaphysical insight because, as we just said, the line between the two is attenuated for Plato.

Is this is a sound principle? Since this is a premise in the immortality proof, if this principle is not granted, the proof will turn out to be unsound even if it passes the test of validity with respect to its logical form. Plato seems to be making a deductive argument here. It is rare to attempt an inductive argument attribution in this case - but we can try it later. Back to considering the principle. It seems easy at first to produce counterexamples to the principle - instances of occurrences that falsify the propounded principle. Here is a ready example. If an object, call it "a", is crushed under a massive avalanche, we can assume that there is no intrinsic deficiency to the things named a, and yet it is surely destroyed by the external impact of the avalanche. So, here is a thing for which no internal deficiency brings about its disjunction. This is an instantiation of the negation of Plato's principle. Hence, we have a falsification of the principle.

Is there any way of rescuing the principle? Start by accepting that the quantifiers ("all," "at least one," etc.) can range over such odd things as absences and also over potential items. This is all controversial, of course. Logic should not care about metaphysical commitments - although a view to the contrary has been popular because of the influence of the Harvard philosopher Quine. But there is a catch with respect to the logic too. Our attempt above to capture the logical form of the principle quantified over things, recall. Instead, we should rather quantify over attributes themselves. We will not attempt this here. Higher-order logics like this are not well-bahaved from a logical point of view but we can bypass all this here. Can the principle be salvaged allowing such relaxation of restrictions?

The item that was crushed by the supposed avalanche can be said to have been destroyed because of its intrinsic deficiency of "not-having-what-it-takes-to-resist-massive-external-force." Students who come upon this reconstruction of the principle usually warm up to it and take it, happily surprised, that the principle is salvagable after all. It is easy to see the point. Yet, at the same time, there may be some characteristic unease about some trick being pulled behind the stage so to speak. This is common in the case of some of the most famous philosophic - and controversial - proofs. What is at stake always is NOT psychological reaction. Some errors, if such there be, are not readily detectable. Unlike rhetoric or advertisement or other enterprises of psychological manipulation, the commitment of philosophic endeavor is to get as deeply as possible into the logical analysis of the argument or the theory.

One could do damage to the principle by trivializing it: for instance, one could show, if possible, that, given this principle, nothing really would be destructible. We could always construct the right attribute - "having-what-it-takes-to-withstand-impact-k" and then negate it to find the corresponding deficiency. Notice, howeever, that this would not show that nothing is destructible; it would only show that we can construct for anything a matching deficiency which that thing has with respect to any conceivable risk or harm. This is another way, though, of saying that we can understand Plato's principle in such a way that is can pass a plausibility test.

It is already surprising that Plato's proof, starting with the principle in the proof, survives so far. Remember that Plato's totality of things comprises immaterial things - Forms and souls/minds. Now, we know from experience (and Plato may think that he can also prove it theoretically) that material things do eventually succumb to risks for which they show vulnerability. The body may escape one illness after another but, eventually, it succumbs to illness. The object that lacks the deficiency with respect to avalanche attacks can in the end be crushed by a bigger or an even bigger avalanche. So, it is indeed destroyed because of its inner deficit which we can consider as its intrinsic ill. (Interestingly, something comes up here that makes common appearances in this area of classical philosophy: Are the ultimate constituents of material nature - the indivisible particles - also indestructible? There is no inner ill that can destroy them, by definition, insofar as they are taken to be indestructible. Plato, however, has no problem here because he does accept material components, all the way down, to be also indestructible and eternal.)

The next key step is to determine what counts as the intrinsic ill of the soul. It cannot be susceptibility to being crushed or punched or assailed by disease since the soul is, by definition, immaterial. This next step is not only crucial but could be a weak link in the argument. Plato does not defend this move in this dialogue but students of Plato's philosophy - perhaps also the followers of Socrates - are presumed to get this point right away. The intrinsic ills of the soul are moral. We are dealing with an analogy, then: what physical ills are to the body, moral ills (vices) are to the soul. This seems to be a stipulated analogy, not an empirically discoverable one that would generate an inductive argument here. Alternatively, one could take it as an empirically attestable analogy but this is harder to see. Once again, many students who come upon this point find something natural about this analogizing jump.

We are now ready for the final stretch: The intrinsic ills of the body ultimately destroy. The intrinsic ills of the soul do not: we don't take such iconic villains as Hitler or Stalin to be ceasing to be persons and mercifully vanish once they pass beyond a threshold of evil conduct. Recall the principle: only its intrinsic ills can destroy a thing. Since the intrinsic ills of the soul do not destroy, nothing can. Assuming that the soul exists, it is indestructible.

As a deductive argument, it is valid but soundness depends on whether the premises are all taken as supported, so they can be accepted as true. This is not obvious, as one would expect.

Formulated as an inductive argument, it would go something like this: we know that the likelihood of succumbing eventually to the characteristic ills of the body - biophysical breakdowns and lack of resistance to mechanical impact - is overwhelming. On the other hand, moral evil, posited as the characteristic intrinsic ill of the soul, does not seem to result in destruction of the person. Hence, it is quite unlikely that its ills kill the soul. As an inductive argument, it is sufficiently strong; but is it cogent - does it have sufficiently supported premises?

Needless to say, not many would be persuaded but, as usual, the argument can be sustained beyond what you might have thought at first. You should be able to discern the vulnerable parts of the argument.

## What is Wrong with the Argument?

Problems with the argument:

1. One may reject the principle that only intrinsic deficiencies can destroy something. When we succumb to a virus, for instance, Plato's principle compels us to understand this as succumbing to our own internal deficiency with respect to immunity to this virus. This makes sense and seems to rescue the principle. But isn't it more informative and complete to say that we succumb to both the lack of relative immunity and the externally introduced virus?
2. The analogy between bodily ill and moral evil for the soul can be questioned. This seems to be a theoretical analogy - one that fits the definitions of terms like "soul" and "moral" within a specific theory - Plato's in this case. The issue then turns on how well supported Plato's overall theory is.
3. The analogy is problematic in another respect. When we draw an analogy between A and B, we proceed by claiming: A and B both have attributes F1, F2, ..., Fk. Now, A has another attribute, Fm. Therefore, it is very likely that B also has this attribute Fm. (This is an inductive argument.) Plato often runs into difficulties on account of a problem here: souls are supposed NOT to be analogous with material things like bodies. If at all, their common attributes would be fewer than attributes they don't share with each other. It is always problematic, then, to try a positive analogy - about attributes the two, body and soul, presumably do share.
4. Why should one accept that more and more evil does not destroy the soul, even accepting Plato's overall theoretical schema? It is actually consistent with Plato's view that the health of the soul is morality, to assume that there may be a point beyond which incurably evil souls are destroyed - and they would be destroyed by their own intrinsic ills in that case too. Plato's Socrates often points to the availability of other proofs backing up the same conclusion but the point is that this particular proof seems vulnerable to criticism.