Phaedo Arguments for Immortality of the Soul

The construction of Plato’s Phaedo is compelling enough to present an argument for the immortality of the soul. In it, he recounts the final days of Socrates who has been condemned to death for corrupting youth in Athens. Plato, ironically uses the Socratic method for concluding that the human soul is immortal. Could it be that Plato is merely like the rest of us mortals who simply crave to believe in the soul’s immortality so that our existence on earth can somehow be justified?

Or, is there a level of substance to his arguments that could actually give credence to the belief that the soul lives on long after our physical self has perished? Plato wasn’t the only philosopher or academic to long for an answer to one of life’s great metaphysical mysteries.

Plato’s arguments for the immortality of the soul are dependent on his belief in the Forms which he also believes emanate from God. While one cannot dispute whether or not the Forms exist, one can also not refute Plato’s absolute belief in God. There is no proof either for, or against the existence of a Supreme Being in the universe. However, we do know that almost every culture and every major religion also believe in this Being’s existence. Swinburne notes that Plato believed in the idea of the soul and the body as separate and therefore one is not contingent upon the other. This empowers Plato to theorize that the soul lives on in a separate existence. He describes Plato’s argument in the following way:

We only know of things ceasing to exist when they have parts; and they cease to exist only when the parts are separated from each other. A house ceases to exist when the bricks are taken away from each other. But the soul has no parts, and so we know of nothing which in the normal course of things would cause it to cease to exist, barring divine intervention. So it is reasonable to suppose that it is naturally immortal (Swinburne 1).

Yet Swinburne proceeds to refute Plato’s argument based on the theory of parts. His primary example is atoms which cease to exist when they’re transformed into energy. But, this is an argument based on a scientific reality (and one borne out of late 20th century knowledge). However, Plato hardly makes a case for immortality based on scientific knowledge but rather philosophical deduction. In Phaedo he writes; “That soul, I say, herself invisible, departs to the invisible world–to the divine and immortal and rational…” (66). In this quote, Plato uses the first argument which is called the Opposites Argument or the Cyclical Argument. The soul is the opposite of the body and while the body must die and decompose, the soul does not. In other words, as the body must inevitably perish, the soul does not because it is the body’s exact opposite. This sounds rather like an ‘other-worldly’ explanation at first. However, if one examines the physical world there are indeed opposites for practically every element and every kind of being. As such, Plato argues that humans themselves contain inherent opposites as well.

His second argument is based on something he called The Theory of Recollection. This theory suggests that we have non-empirical or non-factual knowledge that comes to us by way of the immortality of the soul. “They include the argument (Phaedo 73a—78a; Meno 81b—86b) that humans know many things and have many concepts which they have not learned or acquired on earth” (Swinburne 3). This ‘knowledge’ which comes to us is part of Plato’s theory of the Forms and is also dependent on his theory of the Form. “Our souls contain traces of knowledge (episteme) of the immortal Forms, because they experienced them before being born into the body. We largely forgot what we experienced before birth, but certain events can nevertheless awaken reminiscent traces of the memory” (Keyes & Weber 43).

To some degree, Plato’s Affinity Argument is very much like his Cyclical Argument. This one also assumes or deduces that for everything that exists there is something that is very much unlike it. If there is corporeal form then there are non-corporeal forms and if something can be visible, then something can be invisible. The Argument from the Form of Life argues that all things emanate from the Forms. So, once again Plato’s argument for immortality of the soul returns to this notion of the Forms.

In an analysis of Plato’s arguments, one researcher suggests that it’s possible to deconstruct the first argument, the Cyclical Argument, as being less of provable hypothesis than wishful thinking on Plato’s part. “But since SD (substantive dualism) concludes merely that the soul can exist when the body is destroyed, it provides only a basis for hope that the soul continues to exist after the demise of the body…” (Pakaluk 108).   Pakaluk goes on to suggest that Plato’s entire argument is also very much dependent on the first theory, that of substantive dualism. If there is no duality and there is no separation of soul and body then there is no chance for immortality of the soul. Therefore, he bases the crux of his own analysis on that particular aspect of Plato’s argument. “It is clear that Plato intended the provisional conclusion of SD to serve

as the context of the three initial arguments” (Pakaluk 109).

Pakaluk makes a very good argument. The burden of proof is actually on Plato to provide us with some kind of de facto evidence that there is a separation of body and soul. In fact, Plato’s argument is not only dependent on this notion of separation but the very existence of the soul itself. Plato’s argument for the immortality of the soul is not so much an argument per se but rather a thesis that is an extension of the very nature of Greek philosophy at the time.

For the Greeks, the soul is what gives life to the body. Plato thought of it as a thing separate from the body. A human living on earth consists of two parts, soul and body. The soul is the essential part of the human — what makes me me. It is the part to which the mental life of humans pertains — it is the soul which thinks and feels and chooses (Swinburne 1)

Swinburne raises an essential point here. To a large degree, Greek philosophy and by extension the work of Plato is the result of the desire to prove the existence of a human soul. In this process, they attributed many of the positive aspects of life such as beauty and justice as proof of the soul’s existence. They simply could not imagine that humans could produce such exquisite and important contributions without the notion that our soul is responsible for empowering us to do so. This overall desire to believe in the soul extends to the manner in which Greek philosophers seek to describe it. The body which in many ways is utilitarian and (of course) subject to illness and decay seemed to them, the very opposite of creations such as art, music and poetry. In a very practical way, the Greek society of Plato’s time wanted and needed to believe that some force that was the opposite of a decaying body was therefore responsible for beauty in this world. The notion of a soul and an immortal one fit into their ideas very well.

For Plato, however, the idea of substantive dualism was absolutely essential. There had to be something the very opposite of the body and that was, of course, the soul. “So we should regard SD, strictly, not as a passage which merely precedes the three initial arguments, but rather as that which frames them and sets them off, providing their context” (Pakaluk 109). Augustine suggests Plato’s long-held desire to prove the immortality of the soul is a common one throughout history. He calls it the dilemma of the mind-body connection. In fact, myriads of books, lectures, conferences, workshops and films have been devoted to trying to understand just how the mind and body do connect and if in fact humans have a soul. “Belief in survival in the form of disembodied minds presupposes that people possess an immaterial, nonspatial substance which constitutes the personality” (Augustine par.7).

In light of the scientific information we have today about how the brain functions some might suggest it is a difficult leap to accept Plato’s argument. However, even the world of science fails to explain everything. For example, there is the phenomenon of the near-death experience in which people who have temporarily been declared dead on the operating table have all experienced a similar encounter with a white light and seeing long-lost relatives. There is also the phenomenon known as the out of body experience in which people see themselves having a heart attack, or watch as they’re being operated on in the hospital. These two phenomena do not include the entire branch of psychology that investigates the world of the paranormal which claims to have proof that there is some form of existence beyond death. Are all of these just more examples of wishful thinking? Is it the fact of our mortality that drives us to these philosophical and psychological investigations that will somehow give us proof of the existence of a soul which survives our corporeal demise?

Augustine quotes Bertrand Russell who famously commented on his own thoughts about immortality.

Nevertheless, we cannot base our beliefs on what we want to be true; the truth can only be found by weighing the evidence for a given idea. In the case of immortality, the extinction hypothesis is supported by strong and incontrovertible evidence from the hard experimental data of physiological psychology, whereas the survival hypothesis is supported at best by weak and questionable anecdotal evidence from parapsychology (Augustine par. 24).

He also presents extensive evidence to debunk both near death and out of body experiences. Augustine suggests that these are not factual or scientific evidence but rather random parapsychological, non-scientific investigations.

Keyes and Weber also suggest that Plato’s arguments while nicely written and a valid form of philosophical deduction prove absolutely nothing. They are theoretical at best and at their worst, they are musings of someone who dearly wanted to believe in immortality but never proved it. Swinburne points out the distinct pattern in philosophical thinking by noting that Aquinas came to the same conclusion as Plato because he wanted to. “Aquinas appealed to the fact that humans naturally desire to exist forever and that ‘it is impossible that natural appetite should be in vain’ (Summa contra gentiles II, 79.6). Yet it is far from obvious why that is impossible” (Swinburne 3).

With this quote, Swinburne arrives at the heart of the matter. Human beings want to exist beyond the boundaries of death. The thought of our bodies decaying in the cold ground century after century with the proof of our existence fading away after time is not one we generally like to consider. It is a dark reality and one that causes many anxious-ridden nights for some who cannot comprehend it. Therefore, it is quite possible that Plato was simply no different than the rest of us mere mortals. His words have survived him centuries after his death and in that sense, Plato is indeed immortal. But, it is not his soul we remember but rather his life’s work which inspires philosophers in our own time to take up the same cause.

Still, Plato’s arguments come down to two irrevocable facts. First, there is absolutely no proof that human beings even have a soul. That which Plato and other philosophers have dubbed ‘the soul’ may be merely the synapses firing and neurotransmitters relaying messages inside our brain. Once the brain no longer functions the very core of our existence likely dies with it. Plato, like many others in his own time, and like some in our time, desperately wanted to believe that humans have a soul. In a way, this makes us more human. The idea of a soul is a beautiful one. It somehow decreases the reality of all the negativity in our world. The fact that human beings could have a soul means we are not merely just another animal walking the earth in the long evolutionary history of this plant. It means we have purpose. There is perhaps nothing more compelling to us than our lives have real meaning and we are not simply an evolutionary mistake.

No matter how compelling and how beautiful this notion is, Plato does not prove it. He provides an interesting series of deductions. But, at the end of his arguments, Plato only proves what he already believes. He does not demonstrate any factual evidence for the existence of a soul, or for the existence of God for that matter, which is also an integral part of his arguments. Plato merely proves that he sees the world in a highly specific way and that he is a product of his times.

Swinburne argues that neither Eastern nor Western religions offer any proof for the existence of a soul. Eastern religions base their belief on the notion of reincarnation, an idea which has no proof in scientific fact. Western religions base the belief of the soul on the existence of God, which although a wonderful idea also has no proof in science. He arrives at the following conclusion: “In any case, none of the empirical evidence by itself gives any reason at all for supposing the subsequent existence to be everlasting” (Swinburne 5).

The aspect of Plato’s argument which I feel does not stand up to scrutiny is that of his notion of substantive dualism. On the one hand I agree that for many elements in this world there is something that is its exact opposite. However, there are also many elements which do not have an opposite. Perhaps this is a conclusion I can arrive at because I live in the early part of the 21st century and I have the advantage of centuries of scientific research which Plato did not. Therefore, I think that one need not necessarily be harsh with Plato for coming to that conclusion. At the time he lived, science was still very much in its infancy. We take this scientific knowledge for granted today, but Plato could not. Therefore, one could perhaps easily assume that for everything that exists there is it’s exact opposite.

There is perhaps another reason why Plato came to this conclusion. On a scientific basis, we do know that for ever action in the universe there is its opposite reaction. Perhaps, on some level, Plato was thinking in this regard. In other words, the knowledge that we have a corporeal body that lives and dies in a certain way might also have its exact opposite in a soul which lives on forever.

Another reason I think Plato came to this conclusion is because of the times he wrote in. I believe that to a large degree, all philosophers, scientists and writers are a product of their society. They write within the cultural context they are familiar with and in light of the knowledge that is available to them at the time. Plato is no different in this way. In the Greek society of his day, the notion of the soul was one which people hung on to just as they did with other ‘facts’ which we now know are untrue. They believed in a pantheon of gods and it’s safe to say with a high degree of assurance these gods never existed. Still, they were an integral part of the society in which Plato lived. Thus, he took what he ‘knew to be true’ at the time and formulated his opinions based on that knowledge. I think it is highly likely that if Plato lived today, he would arrive at a much different conclusion.

In the end, I find myself in agreement with Swinburne and Augustine. I do not think that Plato makes a believable argument for the immortality of the soul. However, I do feel that I understand the passion for this endeavor. Life is difficult enough without thinking of our own mortality. Then there is the inexplicable reality that so many people struggle so hard and it seems almost unfair. Take the example of children who live for only a few years then die from a disease such as terminal cancer. We sit back and ask why? Then, as we contemplate the unthinkable, that a young child’s life seems as if it was for naught, we find ourselves thinking back to ideas such as those of Plato — the immortality of the soul. We comfort ourselves with this idea. The child’s soul lives on. Their soul somehow extends into the universe and reattaches itself to another body or lives on in another plane of existence. It is as if we have to believe in these ideas to comfort ourselves and steel ourselves against such loss and tragedy.

Yet, for all of his ability to provide a seemingly logical sequence of deductions, there is nothing in the arguments provided by Plato that I find compelling enough to agree with him. On a personal level, I want to. But that is emotion. On the practical, academic level, I cannot. He has not convinced me. I think in the end, he has merely convinced himself and if so, then perhaps his work was meaningful after all, because it likely comforted him as he faced his own mortality.

However, even though I disagree with Plato’s conclusions, I think it is important to give him his ‘due’ for the complex nature of his philosophical discourse. Given the information he had at the time and the low level of knowledge about the body and the way it works, Plato was a formidable philosophical force. It is a measure of the brilliance of his ideas, whether we agree with them or not, that we continue learn and write about them even today in the 21st century. I think it is safe to suggest that although his body left us a long time ago, in many ways his mind lives on.


  1. Very interesting article; well done I must say. I have read many of Plato’s arguments for the immortality of the soul and like you, have not been convinced. My perspective though is different from yours as I am a believer in Jesus. Yet even so I repudiate Plato’s doctrine for the simple reason that it is not taught in the Scriptures. Rather, they teach a resurrection or raising of the dead to life again. You would not know this though as a perusal of most church/ministry doctrinal statements or sermons on the soul, death, and the afterlife are nearly identical to Plato’s words. So much so that I think these preachers should be slapped with plagiarism charges.

    p.s. I was going to get an Amex card, but after reading your post, decided against it!

  2. Michael,

    That's because before St. Augustine's conversion to Christianity he was involved with the Neoplatonists of the time. One of Augustine's greatest impacts is his synthesis of Platonic and early Christian thought.

  3. Excellent work. I have a serious examination on Plato’s immortality of the soul. Will please help me out, i will appreciate your effort.

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