Aristotle and Plato: philosophical comparison

Plato's Theory Of The Tripartite Soul

The Republic is an influential dialogue by Plato, written in the first half of the 4th century BC. This Socratic dialogue mainly concerns political philosophy and ethics. The political ideas are clarified by picturing a utopia. The Republic also contains the famous allegory of the cave, with which Plato clarifies his theory of ideal forms. The Republic, which is the standard English translation of the title, is somewhat of a misnomer, as the government theorized by Plato resembles an authoritarian aristocracy. Nonetheless, the work is generally recognized a foundational text in political philosophy. The scene of the dialogue is the house of Cephalus at Piraeus, a city beyond the walls of ancient Athens. It was the port of entry and exit for trade into Athens. Socrates was not known to venture outside of Athens regularly. Socrates narrates the whole dialogue the day after it actually took place, to Timaeus, Hermocrates, and Critias, among others.

Plato's philosophy went through a number of stages. As a pupil of Socrates, he began as an analytical and possibly skeptical philosopher. However, throughout his life Eastern philosophy and its representatives at Athens, the Pythagoreans, increasingly influenced him and this took him towards mysticism, and towards number mysticism in particular. A number of recurring themes can be seen in Plato's work: (1) a belief in the immortality of the soul; (2) a rejection of empiricism, represented in Athenian culture at the time by the Sophists; (3) hostility towards the body and sense experience and a belief that virtuous living depends on reason; (4) an attempt to discover the purpose of existence, both for man as an individual and for the world as a whole; (5) a defense of the aristocratic form of government.

In the Republic, Plato puts forward the doctrine of the tripartite soul. The soul, which is originally not connected with a body, has three parts, each corresponding to a certain style of living and psychological orientation. He used the image of a charioteer and two horses to illustrate this. The charioteer represents reason. The better of the two horses is allied to "spirit" which here does not denote another name for the soul, but rather refers to that style of life, which is orientated towards the pursuit of fame and honor, particularly in battle. The bad horse is associated with appetite, instinct and desire. The presence of "spirit" complicates and obscures the basic dualism in this scheme. It is included because it was traditional in Greek society to admire martial valor, but Plato has placed the life of reason above this. The dualism is a dualism of reason against appetite and to live a good life is to reject appetite, instinct and desire and the temptation of physical things in favor of reason and the contemplative life. Appetite allies itself with the body and reason with the soul, but strictly the division of appetite and reason exists in the soul and it is only by giving way to appetite that man falls into association with the body. Thus Plato advances the Pythagorean doctrine that originally man existed as a disembodied soul and became incarnate because he fell from this original state of grace. This makes Plato the originator of the philosophical doctrine of the fall of man, reflected in either a literal or allegorical fashion in Genesis.

Plato makes the comparison between the form of the city and the form of the human being. We are to imagine ourselves to be complex "cities" and the crucial question is: "who's in charge?" How well are you governing this "city," that is, your self? The first task is to see if there are comparable factors of the soul (psyche) that are analogous to the tripartite classes of the polis: Guardian Rulers, Auxiliary Guardians, and Producers. The human soul is complex rather than simple because different aspects of it desire different ends. The appetitive aspect of soul desires sensual satisfaction, for example, for food, drink and sex. The appetites seek not some specific end, for example: Sam Adams Summer Ale, but rather a generic goal: anything quench-worthy. This distinguishes the appetites from the rational soul. Socrates finds in the soul conflicting tensions: one in the direction of satisfying the appetite, the other in the direction of frustrating the appetite.

Reason is the calculating part of the soul: the rational soul. There can be found in the same person the irrational desire to drink and the rational resistance to drink because of the bad consequences of drinking. An example would be the offer to a starving man of a cake the starving man knows to be poisoned. The persistent desire on the part of the appetite, in contrast to the rational part which resists it at all costs, shows the separation of these aspects of the psyche. Finally, the fact that anger sometimes makes war against the appetites reveals the third part of the tripartite soul: the spirited soul (anger, assertion, aggression).

The nature of the mental processes has been an issue of central importance ever since man started to study the human mind. Plato made the first systematic effort. One of his major philosophical models, the tripartite structure of the soul, was not only a pioneering effort, it has influenced virtually every thinker interested in the human mind ever since. It still exerts a powerful influence on the organization of theory and research in present-day psychology. In this, psychology seems to share the fate of Western philosophy. The eminent philosopher A.N. Whitehead is quoted as follows: "The safest general characterization of the European philosophical tradition is that it consists of a series of footnotes to Plato."

Popper notes: "Plato's structure of the soul is characterized by an unstable equilibrium - indeed a schism -between its upper functions, reason and will, and its lower functions, the instincts or appetites."

In Book IV of the Republic, Socrates provides a definition of justice. This definition bears strong resemblance to the two definitions of justice put forward in Book I. Cephalus ventured that justice was the honoring of legal obligations, while his son Polemarchus suggested that justice amounts to helping one's friends and harming one's enemies. These two definitions are linked by the imperative of rendering what is due, or giving to each what is appropriate. This same imperative finds variant expression in Plato's definition of justice as a political arrangement in which each person plays the appropriate role. What is due to each person is rendered all at once. Each is assigned the role in society that best suits their nature and that best serves society as a whole. In one sense, Polemarchus and Cephalus were not that far off the mark. However, in following the traditional notions, they were thinking about justice as a set of actions, rather than as a structure to society, a phenomenon that spreads out over a city as a whole.

In addition to the definition of justice, we also get the definitions of four other virtues in this section. The city's courage, Socrates tells us, is located in the auxiliaries, because it is only their courage that will affect the city as a whole. Yet right after making this claim, he goes on to tell us that what the auxiliaries possess is not simply courage but something he calls "civic courage." Many scholars have interpreted civic courage as a kind of second-rate courage. What the auxiliaries have, Socrates tells us, is the right beliefs about what is to be feared and what is not to be feared. Their courage is founded upon belief, rather than knowledge. Later in the book, he indicates that real virtue must be founded upon knowledge, suggesting that virtue based on habit or belief and not knowledge will fail when the going gets very tough. Since only the guardians possess knowledge, only the guardians can be truly virtuous or courageous.

Now that Socrates has identified societal justice, he turns to look for individual justice. Justice in the individual, as in the city, involves the correct power relationship among parts, with each part occupying its appropriate role. In the individual, the "parts" are not classes of society; instead, they are aspects of the soul, or sources of desire.

In order to make the case that individual justice parallels political justice, Socrates must claim that there are precisely three parts of the soul. By cataloging the various human desires, he identifies a rational part of the soul that lusts after truth, a spirited part of the soul that lusts after honor, and an appetitive part of the soul that lusts after everything else, including food, drink, sex, and especially money. These three parts of the soul correspond to the three classes in the just city. The appetite, or money-loving part, is the aspect of the soul most prominent among the producing class; the spirit or honor-loving part is most prominent among the auxiliaries; and reason, or the knowledge-loving part, is dominant in the guardians.

So, according to Plato's theory of the self, we are fundamentally divided beings: we are a war zone of competing drives. However, we do not have to be like that. If a correct and healthy order is maintained between the three elements of the soul we will be in a healthy condition and will flourish. And what is a correct order? Well, of course it is one in which reason plays it's rightful and natural role of master and, aided by "spirit," controls the desiring appetites. A person whose soul is arranged in this way, a person whose self is governed in this way, will live a healthier, happier, and better life than the person whose soul is governed by appetite. Ultimately, then, the answer to the question "why be moral?" is because that is the healthiest, most natural, and happiest way for a human being to live. The just person lives a well-balanced, harmonious and happy life; the unjust person lives a life of excess, conflict and misery. It should be clear then, according to Socrates, which life is the best one to choose. We need to look at Plato's other recommendations as to how reason should manifest its dominion. The clearest, I believe, is to be found in Plato's portrait of the reasonable man in the Republic at 571e-572a:

But when, I suppose, a man's condition is healthy and sober, and he goes to sleep after arousing his rational part and entertaining it with fair words and thoughts, and attaining to clear self-consciousness, while he has neither starved nor indulged to repletion his appetitive part, so that it may be lulled to sleep and not disturb the better part by its pleasure or pain

Just relations between the three parts of the soul mirror just relations among the classes of society. In a just person the rational part of the soul rules the other parts, with the spirited part acting as helper to keep the appetitive in line. Compare this to the city where the truth-loving guardians rule, with the honor-loving auxiliaries acting as their helpers to keep the money-loving producers in line. What it means for one part of the soul to "rule" the others is for the entire soul to pursue the desires of that part. In a soul ruled by spirit, for instance, the entire soul aims at achieving honor. In a soul ruled by appetite, the entire soul aims at fulfilling these appetites, whether these be for food, drink, sex, fine material goods, or hordes of wealth. In a just soul, the soul is geared entirely toward fulfilling whatever knowledge loving desires reason produces. The idea that the appetites should be sublimated is present elsewhere in the Republic at 485d-e:

But, again, we surely are aware that when in a man the desires incline strongly to any one thing, they are weakened for other things. It is as if the stream had been diverted into another channel. So when a man's desires have been taught to flow in the channel of learning and all that sort of thing, they will be concerned, I presume, with the pleasures of the soul in itself, and will be indifferent to those of which the body is the instrument if the man is true and not a sham philosopher.

Socrates has now completely fulfilled his first goal: he has identified justice on both the political and individual levels. Yet in giving an account of justice, he has deviated from our intuitive notions of what this virtue is. We tend to think of justice as a set of actions, yet Socrates claims that justice is really a result of the structure of the soul. After identifying individual justice, he demonstrates that a person whose soul is in the right arrangement will behave according to the intuitive norms of justice. He needs to show that the notion of justice we have just arrived at is not counter to our intuitions, that this notion accounts for our intuitions and explains them. Socrates points out that since our just person is ruled by a love of truth, he will not be in the grips of lust, greed, or desire for honor. Because of this, Socrates claims, we can rest assured that he will never steal, betray friends or his city, commit adultery, disrespect his parents, violate an oath or agreement, neglect the gods, or commit any other acts commonly considered unjust. His strong love of truth weakens urges that might lead to vice.

Socrates concludes Book IV by asserting that justice amounts to the health of the soul: a just soul is a soul with its parts arranged appropriately, and is thus a healthy soul. An unjust soul, by contrast, is an unhealthy soul. Given this fact, we are no w in a position to at least suspect that it pays to be just. After all, we already admitted that health is something desirable in itself, so if justice is the health of the soul then it too should be desirable. Plato feels that he is not ready just yet to make the argument in favor of justice's worth. He puts off the definitive proofs until Book IX. The passage on the soul is itself a grand metaphor for the divisions in the city: the reality of the soul is the reality of the idea of the best city. As one scholar has argued, metaphor and political knowledge are deeply interrelated and "the great metaphors of political theory are deliberate contrivances."

The examples, in this sense, are also devices that allow us to speak about puzzling notions such as the divisions in the soul in ways where logical propositions are inadequate. The mode of metaphoric reading requires us to make sense of these devices as central to understanding Plato's idea of the tripartite soul.