Soul and Body in Plato

Soul and Body in Plato and Descartes

Mind/Soul and Body in Plato and Descartes

To this day, the problem of the mind-body relationship has not been resolved. Indeed, some have rejected all commitment to mentality, according to Jaegwon Kim, while others have resurrected a Schopenhauerian pessimism that says that the problem is insoluble (Kim 580). To understand the problem, take the example of a corpse. A dead body appears to lack animation. It does not move, speak, or respond to stimuli. Its eyes cannot see. Yet one can observe its presence as an object, a body, with physical shape, dimension, depth, and weight. Even the brain, if one were to open the skull of a dead person, continues in bodily form. What we call a dead body does not simply disappear as soon as it loses the power of animation. This seems to lead to the conclusion that there is something besides the body and the brain that is the animating force within each animated body. The question, then, is how the two -- soul and body -- are related. Are they related because they are of the same substance? Or are they completely different in substance? Is the soul a physical thing? And does it vanish at physical death or remain immortal and imperishable because it is immaterial substance? These constitute the questions that this paper wants to discuss. It will focus on two prominent views from the history of philosophy, those of Plato and Descartes, to formulate an independent perspective.

The issues of soul/body puzzled Plato. He gave some answers to them in his philosophical work, the Republic. He seems to assert a dualism in which the soul is related to the body while the body is alive, but ultimately unrelated to the body after death. The soul is a different thing than the body. Julia Annas writes, "Plato never doubts that when I ask what I, myself, really am, the answer will be that I am my soul, rather than my animated body" (Annas 65). What are they, then, and how are they related?

The soul in Plato is divided into parts. In book four of Republic, Plato talks of the "three parts in his soul" (435c). These are broken into reason, emotion, and desire/appetite (436a). His argument is based on motion. Thirst, for example, drives a person "like a beast" to drink (439b). Yet there is some part of the soul that can make a thirsty person withhold drinking. This is the distinction between the calculating rational part and the irrational appetitive part. In addition, there is a third passionate part of the soul. This thumos is what some might call spirit, as in a spirited performance at the ballet or at a football game. One of Plato's examples of this in Republic is the city guardian who must possess a soul of courage that is spirited (375a-b). It encompasses the emotional side of life such as anger (439e).

The three parts can be in conflict. Each part has its driving pleasures and can rule the soul (580d-581c). For example, one's emotions can lead to repressing hunger for a passionate goal. But it can also be negative. If someone is badly governed (unjust), they are driven by tyrannical pleasures and lack self-control (579b). This is where Plato sees the soul as imprisoned in the body. Plato links this with a civil war in the human soul, and alliances can sometimes be made between the three different parts. His moral conclusion, however, is that the rational part should rule "since it is really wise and exercises foresight on behalf of the whole soul, and for the spirited part to obey it and be its ally" (441e). The pleasures of the body and emotion must be abandoned as rebellious parts of the soul. Guidance by the rational part of the soul leads to the best form of life. It has the more comprehensive view of things. The passionate and desiring parts of the soul are short-sighted. Reason's guiding hand is for the good of the whole, not just of itself (586d), and it is the "least disturbed or altered by any outside affection" (380e). For these reasons, he prioritizes the rational element.

So what is this complex soul's relation to the body? Annas writes, "In the Timaeus the soul's parts are located in different parts of the body, in ways which encourage reason (in the head) to dominate spirit (in the upper body) and desire (in the lower body)" (Annas, 68). The soul is obviously connected to the body. It is not exactly clear how. Plato never explains how the immaterial inhabits the material. At the same time, in Plato's view the soul is immortal. It survives disconnection with the body. So there must be some part of the soul that is free from involvement with the body. There must be something of the soul that is unaffected by the physical world of senses or connection to it. Here it seems to be reflection, or mind. Perhaps it is the soul's ability to think about things independently of sense perception. This mind part of the soul is what goes beyond the visible world to contemplate mental objects or forms. In other words, the body has sense perceptions of visible things, but the mind contemplates the invisible things, the changeless forms (507b). In his famous cave analogy, he says that some virtues of the soul are like the body, but the virtue of reason belongs to something divine (518e). At death, the soul leaves the body that imprisons it. The rational part of the soul is drawn away from the lawless corporeal things that corrupt the soul but do not kill it (610d). Death is a release to purity. Plato says, "But to see the soul as it is in truth, we must not study it as it is while it is maimed by its association with the body and other evils . . . But as it is in its pure state" (611b). All souls exist apart from the body after death, he asserts in book ten of Republic.

This view of the soul seems overly driven by morality and disconnection with the real world. Plato denigrates the body because he wants to elevate reason. He seems to think that the body is nothing but a corrupting influence, a diversion away from beautiful contemplation. This is problematic if one sees the soul as intimately connected with the body. It is hard to understand how something invisible can exist apart from having physical form. This means that it is not at all as clear as Plato thinks that the soul is immortal. His arguments are more like presuppositions than conclusions. By prioritizing the mental rational part of the soul, he can talk about invisible forms in some pure reality. There is no proof for this other world, or for the notion that the rational soul exists beyond death. There is no proof that contemplation is possible apart from a physical body doing the contemplation. Can the mental aspect function without an organic body? Is thought possible without a physical brain?

In terms of Plato's division of the soul into three parts, this is less controversial. There do seem to be animated differences between thinking, feeling, and sensing. All of them are mixed and interrelated in a confusing way within the body. To make them so distinct is perhaps impossible. But conceptually and practically, a human feels all these different forces. The main problem is in linking something like the appetites with the soul. These seem more just a function of the body, the way the body maintains its survival. Not just thirst, but also procreation and sexual desire, the avoidance of pain, etcetera. In this view, even emotion and reason can be linked to the body in its organic existence. From this perspective, while the three parts of the soul may interact, there is no reason to prioritize reason over the other two. The only reason would be a type of morality. Without the moral argument, the other parts of the soul, linked to bodily realities, can be seen in a more positive light. They need not be corrupting or evil.

Descartes's view of the mind/body problem comes mainly in the sixth of his Meditations. He sets his view up in the second meditation with the notion of an extended body in space for which "power of self-movement, like the power of sensation or of thought, was quite foreign to the nature of a body" (VII: 26). Here it is the mind that moves the body, much as Plato had asserted. Bodies require some animating force invested in them to gain animation. He comes to believe in his existence, but it is proven only by his being a thinking being. He clearly believes that what defines him is his mind, not his body. Later in the third meditation he says, "I conceive of myself as a thing that thinks and is not extended" (VII: 44). In other words, like Plato, the body is inferior and its substance is irrelevant for true and certain knowledge. The intellect with its faculties (judgment, imagination, memory, free will, etc.) is most important.

The sixth meditation is the crucial one. He shows the body as "an extended, non-thinking thing" (VII: 78). This is accepted as being close to who he is, but not as close as the mind part. "And accordingly," he says, "it is certain that I am really distinct from my body, and can exist without it" (VII: 78). In other words, the mind and the body are separate, not dependent on each other. This is not exactly an argument for the immortality of the soul in the Platonic way. but, as Wilson says, "He now determines that there is no reason why the death or destruction of the body should entail the death or destruction of the mind" (Wilson 177). It is logically possible. Furthermore, the mind is divided into "modes of thinking" such as imagination and sensory perception. These are different forms of mental substance. They are different than corporeal or extended substance. Descartes has a more realistic view of the soul as mind, and does not disparage the body like Plato does. However, he continues the priority of mind over matter, and a dualism that puts them as totally different substances whose connection is mysterious.

So how are mental and corporeal substance connected? His principal example is pain. He feels intellectual distress during physical pain. If there were no essential connection, he would not feel such pain. This proves for him the intermingling of mind and body. He uses additional examples of hunger and thirst. Finally, he says he is affected unfavorably by bodies close to his sometimes. This tells him that "my body, or rather my whole self, in so far as I am a combination of body and mind, can be affected by the various beneficial or harmful bodies which surround it" (VII:81). This is a kind of partnership. At the same time, it seems to contradict the clear substantial distinction of body and mind. So Wilson says, "The intermingling is an as-it-were intermingling, an impression as of intermingling that is itself an idea" (Wilson 203). That is, it is a real union, but one only in thought.

Using examples of fire and stars, perceived heat and light, he shows that "the proper purpose of the sensory perceptions given me by nature is simply to inform the mind of what is beneficial or harmful for the composite of which the mind is a part" (VII: 83). They need not resemble the actual state outside of him, as though the mind held copies of them. Heat and pain are not in the external things but in the perceiving body. This shows how he views the relationship of mind and body, and the priority he places on the mind. The mind is the place for knowledge, not the physical body. Meanwhile, he seems to take a rather mechanical view of the human body, comparing it with a clock that operates by the laws of nature. He says he may consider the body as a machine that could perform all the same movements as it would when controlled by a will or mind. The body receives and reacts to the environment even without the mind. Here he also seems to link sense experience with action, or dispositions to act. Things show us what is useful or not to do or to respond. They are signals. Obviously, the will or mind is what animates the body, but not what determines whether or not a body gets thirsty or sick. So there is some concept of "nature" (or God) that Descartes uses to explain the body apart from the mind.

Further, the body is divisible by nature, whereas the mind is absolutely indivisible. One can cut off an arm and a part of the mind does not disappear. And the faculties are united, unlike in Plato where they are composite and in conflict: "it is one and the same mind that wills, and understands and has sensory perceptions" (VII: 86). He goes on to localize the mind in the brain, unlike Plato who disperses its separate parts. It is affected only by the part of the brain that contains common sense. Yet the brain is linked to all parts of the body through nerves. To this extent, Descartes demonstrates greater familiarity with physiology than Plato, and how sensations are distributed through the body. He conceives of these as signals (we would say impulses) that produce one corresponding sensation and are conducive to health.