Critics of The Republic, Plato’s contribution to the history of political theory, have formed two distinct opinions on the reasoning behind the work. The first group believes that The Republic is truly a model for a political society, while the other strongly objects to that, stating it as being far too fantastic for any society to operate successfully by these suggested methods. In an exchange between Crito and Dionysius, this argument is first introduced, with Crito siding with those who agree that The Republic is a realistic political model, and Dionysius arguing on behalf of those who doubt it as being realistic, claiming it to be a criticism of politics in general.
Both sides have legitimate arguments, and there is evidence within the text to support each opinion. When Plato wrote Gorgias, he made it clear where exactly he stood on his personal involvement in politics (Cornford 1941, xix). “Unlimited power without the knowledge of good and evil is at the best unenviable, and the tyrant who uses it to exterminate his enemies and rivals is the most miserable of men--a theme to be further developed in The Republic (Cornford xx).” But here, Plato was referring to the politics of his time, and critics who sided with Crito believed that The Republic was Plato’s way of introducing a political system in which he would feel comfortable supporting (Plato 204). Conversely though, The Republic itself is summed up this way:
Well, one would be enough to effect all this reform that now seems so incredible, if he had subjects disposed to obey; for it is surely not impossible that they should consent to carry out our laws and customs when laid down by a ruler. It would be no miracle if others should think as we do; and we have, I believe, sufficiently shown that our plan, if practicable, is the best. So, to conclude: our institutions would be the best, if they could be realized, and to realize them, though hard, is not impossible (Plato 210-211).

These institutions of which Plato speaks are described in the body of The Republic, and not only does Plato explain how they are carried out in current society, but he offers his own alterations, which is the primary cause of the arguments over the content of the book (Plato 222).
In his fifth chapter, entitled “The Problem Stated,” Plato introduces what he

believes to be wrong with the current system of politics (Plato 41). He starts by

describing the Social Contract theory (Plato 53), the method used during his time, a method

Plato rejected. It says:

all the customary rules of religion and moral conduct imposed on the individual by social sanctions have their origin in human intelligence and will and always rest on tacit consent. They are neither laws of nature nor divine enactments, but conventions which man who made them can alter, as laws are changed or repealed by legislative bodies. It is assumed that, if all these artificial restraints were removed, the natural man would be left only with purely egotistic instincts and desires, which he would indulge in all that Thrasymachus commended as injustice (Plato 41-42).

In response to this description, Plato wrote,

First, I will state what is commonly held about the nature of justice and its origin; secondly, I shall maintain that it is always practiced with reluctance, not as good in itself, but as a thing one cannot do without; and thirdly, that this reluctance is reasonable, because the life of injustice is much the better life of the two--so people say. That is not what I think myself, Socrates; only I am bewildered by all that Thrasymachus and ever so many others have dinned into my ears; and I have never yet heard the case for justice stated as I wish to hear it (Plato 43).

Throughout this chapter, Plato makes a point to say how difficult it is to do what is right, since it seems so much easier to take the easy way out, to do the wrong (Plato 49). And in summing up this chapter, Plato had one final contribution, “You must not be content with proving that justice is superior to injustice; you must make clear what good or what harm each of them does to its possessor, taking