There is a natural progression from Plato's theory of Forms to his philosophy of ethics. If one can be deceived by appearances in the natural physical world, one can be equally deceived by appearances in the moral realm. The kind of knowledge that helps one to distinguish between shadows, reflections, and real objects in the visible world is just the kind of knowledge that we need to discriminate between the shadows and reflections of the genuinely good life. Plato believed that just as there could be no science of physics if our knowledge were limited to visible things, so also there could be no knowledge of a universal Idea of Good if we were limited to the experiences we have of particular cultures.
The well-known skepticism of the Sophists illustrated to both Socrates and Plato this connection between knowledge and morality. For the Sophists, believing that all knowledge is relative, denied that people discover any stable and universal moral standards. Their skepticism led the Sophists to some inevitable conclusions regarding morality, namely (1) that moral rules are fashioned deliberately by each community and have relevance and authority only for the people in that place; (2) that moral rules are unnatural, that men obey them only because of the pressure of public opinion, and that if their acts could be done in private, even the "good" men would not follow the rules of morality: (3) that the essence of justice is power, or that "might is right"; and (4) that in answer to the basic question "what is the good life?" one would have to say that this is the life of pleasure. Against this formidable teaching of the Sophists, Plato brought forth the Socratic notion that "knowledge is virtue" and supplied it with a philosophical elaboration the chief ingredients of which were (1) the concept of the soul, and- (2) the theory of virtue as function. The Republic by Plato is the book that is devoted to a long discussed question, what is justice? The question is really tremendous, therefore can be judged from different perspectives. The Republic is a vivid example of a justice view as explained by Plato and his teacher Socrates.
Justice must be considered narrowly. Suppose two men have a difference of opinion and are unable to agree. They then go to a judge. He "judges" between them, most probably according to his best opinion, of what is justice in this specific case. But many men and women never emerge during their whole lives in a court as opponents. They might then say that justice is not a broad problem, at least it has not been broad enough ever to touch them.
Plato and Socrates speak about justice in a much broader sense. They consider everything in life to be a matter of justice. Your own position in life is a matter of justice. All of your relations to others are a matter of justice. How society is organized and holds together is a matter of justice. Who rules and who obeys is a matter of justice.
Who has much sophisticated goods and who has little sophisticated goods is a matter of justice. Justice is different from mere official relationships. Justice is what is really due you rather than what is legally due you. Justice is broader than the statutes and laws of the land.
Moses, as it will be remembered, was very successful in regard to the problem of a simple statement of the law. It had to be uncomplicated to become universally usable. Socrates and Plato worked on the same problem. They, too, had to have a simple definition of justice in order to make it usable. The problem discussed can be discriminated in terms of justice and injustice, as well as in terms of good and evil. In the Republic, Plato describes the soul as having three parts, which he calls reason, spirit, and appetite.
He derived this tripartite conception of the soul from the common experience of internal confusion and conflict that all men share. When he analyzed the nature of this conflict, he discovered that there are three different kinds of activity going on in a person. First, there is an awareness of a goal or a value, and this is the act of reason. Secondly, there is the drive toward action, the spirit, which is neutral at first but responds to the direction of reason. Last, there is the desire for the things of the body, the appetites. What made him ascribe these activities to the soul was his assumption that the soul is the principle of life and movement: The body by itself is inanimate, and, therefore, when it acts or moves, it must be moved by the principle of life, the soul.
That the soul has three parts followed, Plato thought, from the fact that people's internal conflict indicated different springs of action at work. The reason could suggest a goal for behavior only to be overcome by sensual appetite, and the power of the spirit could be pulled in either direction by these sensual desires. Plato illustrated this human condition by his striking figures in the Phaedrus, where he portrays the charioteer driving two horses. One horse, says Plato, is good, "needs no touch of the whip, but is guided by word and admonition only." The other is bad, "the mate of insolence and pride... hardly yielding to whip and spur." Though the charioteer has a clear vision of where to go and the good horse is on course, the bad horse "plunges and runs away, giving all manner of trouble to his companion and the charioteer... ." Throughout his account of the moral experience of human beings, Plato alternates between an optimistic view of their capacity for virtue and a rather negative opinion about whether they will fulfill their potentiality for virtue.
This double attitude rests upon Plato's theory of moral evil. We have already said that evil or vice is caused by ignorance, by false knowledge. False knowledge occurs when the passions influence the reason to think that what appears to bring happiness will do so, although in reality it cannot. When the appetites thus overcome the reason, the unity of the soul is adversely affected. While there is still a unity, this new unity of the soul is inverted, since now the reason is subordinated to the appetites and has thereby lost its rightful place. What makes it possible for this disordered unity to occur, or what makes false knowledge possible? In short, what is the cause of moral evil? The cause of evil is discovered in the very nature of the soul and in the relation of the soul to the body.
Before it enters the body, says Plato, the soul has a prior existence. As we have seen, the soul has two main parts, the rational and the irrational. This irrational part in turn is made up of two sections, the spirit and the appetites. Each of the two original parts has a different origin. The rational part of the soul is created by the Demiurge out of the same receptacle as the World Soul, whereas the irrational part is created by the celestial gods, who also form the body. Thus, even before it enters the body, the soul is composed of two different kinds of ingredients.
In the soul's prior existence, the rational part has a clear vision of the Forms, of truth, though at the same time, the spirit and appetites already, by their very nature, have a tendency to descend. If one asks why it is that the soul descends into a body, Plato says that it is simply the tendency of the irrational part, the part of the soul that is not perfect, to be unruly and to pull the soul toward the earth. For Plato says that "when perfect and fully winged she [the soul] soars upward... whereas the imperfect soul, losing her wings and drooping in her flight at last settles on the solid ground there, finding a home, she receives an earthly frame... and this composition of soul and body is called a living and mortal creation." The soul "falls," and that is how it comes to be in a body. But the point is that the soul has an unruly and evil nature in its irrational parts even before it enters the body, so that in one sense the cause of evil is present even in the soul's pre-existent state.
It is in "heaven" that the soul alternates between seeing the Forms or the truth and "forgetting" this vision, whereupon its decline sets in. The soul has the inherent possibility of disorder, so that when in fact disorder does occur in the soul, the cause of evil is to be located within the soul itself, being the product of ignorance and forgetfulness of the vision of reality. Evil, in this view, is not a positive thing but is rather a characteristic of the soul wherein the soul is "capable" of forgetfulness, and it is those souls only that do forget the truth that in turn descend, being dragged down by the attraction for earthly things. The soul, then, is perfect by nature, but one aspect of its nature is this possibility to lapse into disorder, for the soul also contains the principle of imperfection, as do other parts of creation.
Upon its entrance into the body, however, the difficulties of the soul are greatly increased. Plato believed that the body stimulated the irrational part of the soul to overcome the ruler ship of reason. The soul's entrance into the body, therefore, is a further cause of disorder or the breakdown of the harmony between the various parts of the soul. For one thing, when the soul leaves the realm of the Forms and enters the body, it moves from the realm of the One to the realm of the many.
Now the soul is adrift in the bewildering sea of the multiplicity of things and subject to all sorts of errors because of the deceptive nature of these things. In addition, the body stimulates such activities in the irrational part of the soul as the indiscriminate search for pleasure, exaggerating such appetites as hunger, thirst, and the desire to create offspring, which in turn can become lust. In the body the soul experiences sensation, desire, pleasure, and pain as well as fear and anger. There is love, too, for a wide range of objects varying from the simplest morsel that can satisfy some taste to a love of truth or beauty that is pure and eternal. All this suggests that the body acts as a sluggish encumbrance to the soul, that the spirit and appetites of the soul are peculiarly susceptible to the workings of the body. In this way, then, the body disturbs the harmony of the soul, for the body exposes the soul to stimuli that deflect the reason from true knowledge or that prevent the reason from recalling the truth it once knew.
According to Plato, there are only absolute truth, goodness and beauty that exist. Plato believes in the existence of absolute truth, goodness, and beauty beyond our unclear and confused view of things is the reality of eternal standards and structures. There are still a lot of more less good and beautiful things, meaning that there is only one absolute reality. There exists a great number of more less just individuals; there is only one absolute justice present (idea or an ideal of justice). It is impossible for humans to achieve absolute truth, goodness, and beauty.
However, the only belief in their existence is what should motivate people to strive to it, think about it, intentionally follow this idea, and try to inquire something new. The absolute is a "flying perfect" (as Emerson calls it in "Circles"). This notion prompts people to act, though it avoids them and stays ahead of them. This is the ethical meaning of Plato's "theory of forms." It is also the fundamental nature of every moral idealism. Whatever motives may be attributed to Plato, there is one thing Plato himself would insist on: Plato never invented the forms; he saw them. In this meaning, Plato's dialogues, including the Republic, are not meant to draw attention to themselves, but, like signs, are meant to point over themselves and to point the reader over himself to see the imperceptible structures prevailing over all things..