Plato's Republic: Two Definitions of Justice Compared

Introduction: Justice in Plato's Republic

According to Plato, "justice is the excellence of the soul, and injustice the defect of the soul" (20). Another definition, however, is that justice is "the repayment of a debt" (4). This is a rather narrow definition, and it is one that Socrates unpacks — but he does so in order to get to the heart of the underlying meaning. The just man is one who pursues the good, while the unjust man is one who pursues evil. As is always the case with Socrates, everything must eventually come around to a definition of the good, which Plato defines in the dialogue as transcendental ideals that objectively exist as universals. To know justice is, as Socrates explains in the Allegory of the Cave, to pursue the ultimate reality, which exists high above, where the source of all good is to be found — in God. This paper compares and contrasts the two definitions of justice and explains how justice, as ultimately defined by Plato, is alignment of the soul with the one, the true, and the good.

The first definition — that justice is excellence of the soul — is not a great deal different from the second — that justice is the repayment of a debt. If Socrates can show that all men are indebted to the higher good that has filled them with life, then he can show that no man is just who has not repaid the debt — that is, returned that life to its source. Plato takes care in The Republic to constantly reiterate how difficult it is to apprehend a concept such as justice, namely because it is so difficult for men to understand what is meant by the good. Without a proper conception of the good, one cannot have a proper conception of justice. And yet so many people go about their lives thinking that they not only understand justice perfectly well but that they are also good men.

Justice as Excellence of the Soul and the Allegory of the Cave

Plato uses the Allegory of the Cave to dispel this notion. He describes most men as like those living in a cave, watching shadows on the wall and thinking they are seeing real life. But one man turns around and sees that real life is outside the cave — that what he has been watching are merely shadows. He leaves the cave and pursues the light, coming closer to understanding reality, while the others stay behind, still engrossed in watching their own shadows. Those who go to the courts and argue the law are like the men still in the cave, talking "about the images or the shadows of images of justice" (Plato, Republic Bk. 7).

Likewise, in his conversation with Thrasymachus, Socrates attempts to bring his interlocutor to an adequate definition of justice — but both fail to arrive at one, leaving Socrates to lament rather comically:

Socrates and Thrasymachus: The Limits of Definition

"So have I gone from one subject to another without having discovered what I sought at first, the nature of justice. I left that enquiry and turned away to consider whether justice is virtue and wisdom or evil and folly; and when there arose a further question about the comparative advantages of justice and injustice, I could not refrain from passing on to that. And the result of the whole discussion has been that I know nothing at all. For I know not what justice is, and therefore I am not likely to know whether it is or is not a virtue, nor can I say whether the just man is happy or unhappy." (21)

Plato thus shows that one can waste many words attempting to define justice, but there is no use doing so unless one can understand goodness first of all.

Conclusion

The definitions of justice — as excellence of soul and as repayment of debt — are both ways to begin to understand the concept, but neither wholly explains its meaning, as both are dependent upon a greater understanding of the good. Plato insists in the Allegory of the Cave that the good can only be known by climbing upward in the mind to the source of all things, toward the good and the true. One must leave behind the shadows of thought and encounter the Reality above.