In response to Crito's plea that Socrates agree to be rescued, Socrates answers that Crito's enthusiasm is only well exhibited if it is right and proper. When considering arguments, Socrates suggests, one ought only to take heed of those that seem right upon reflection. It would be wrong for Socrates to abandon the arguments he propounded in the past simply because his life is now in danger. If he is to change his behavior now, it should be for reasons other than his impending death.
Crito agrees with Socrates that not all opinions are of equal value--that some are sound and some are flawed--and that one should follow the opinions of the wise, which are sound, and not of the foolish, which are flawed. The opinions of the wise in any matter come from experts in those matters. Thus, if a man considered everyone's advice regarding his health, he might not benefit, but if he listens only to his doctor, he would be much better off. Someone who disobeys or ignores the advice of his doctor will surely suffer, and his body will deteriorate.
Analogously, then, Socrates refers to the part of us which is harmed by unjust actions and benefited by just actions. (This "part of us," left ambiguous here, is referred to as the soul in later works of Plato's.) Socrates suggests that this part of us is far more valuable than the body, and that life would hardly be worth living if it were damaged. In this case, it is of even greater importance not to take anyone and everyone's advice, but to listen only to experts who know best how to handle such matters. Crito, then, is wrong to worry about public opinion regarding matters of justice: he should ignore it altogether, paying heed only to those who are wise about justice. In response to Crito's objection that, though they may be ignorant, the public has the power to put a man to death, Socrates replies that this has no bearing on the argument whatsoever. After all, Socrates is not concerned with what he must do in order to live, but what he must do in order to live well--that is, honorably and justly. Thus, Socrates and Crito should not worry about the public or about Socrates' sons or anything else, but should ask themselves only whether or not arranging an escape would be just and honorable.
Agreed upon this point, Socrates moves to a variation of one of his more famous claims: that no one can ever knowingly do wrong. Here, he suggests that one should never, under any circumstances, knowingly commit an injustice. So even in retaliation, it is wrong to inflict an injury upon someone who has wronged you, since inflicting injury is a form of injustice. Socrates also persuades Crito that one does injury, and therefore injustice, in breaking an agreement. His conclusion, then, is that if he leaves his prison without first persuading the state to let him go, he is breaking his agreement to abide by the laws of the state, and is thus causing the state an injury. Crito confesses that Socrates' reasoning has left him confused.
The most interesting and most famous part of the Crito comes in the sections that follow, where Socrates imagines the voice of the Laws of Athens explaining why he should stay in prison and face death. By personifying the laws in this speech, Socrates will treat the agreement between the individual and the state in the same way as he might treat an agreement between two individuals. Even in this section, we get a sense of Socrates' rhetorical thrust in several cases of personification. At 46b, he refers to arguments as his "friends," suggesting that he shouldn't listen to the advice of all his "friends," but only to the sound ones. At 48a, he speaks of the truth is as being on the side of the expert in affairs of justice. Finally, at 49e-50a, Socrates discusses the question of persuading the state to let him go, and whether he would be breaking his agreement with the state if he escaped. In these acts of personification, Socrates casts all political and ethical matters as an interaction between two people. Political matters, in spite of their complexity, are just the same as personal matters except one is dealing with one's relationship with the state and its laws rather than with a close friend.
A salient issue in the Crito is the question of how consistent it is with other Platonic dialogues--the early dialogues in particular. A number of possible inconsistencies raise themselves in this section (though the most important ones are raised later, in the speech of the Laws of Athens). At 46b, Socrates speaks of "the arguments which I used to expound in the past," a claim which sounds more like Plato than Socrates. Socrates consistently claims that he has no arguments of his own, that he is only interested in exposing the weaknesses of others' arguments. At the same time, his claims that no one ever knowingly does wrong, or that knowledge is virtue, do seem like arguments, and here he seems to accept this. Later in his career, Plato would use the character of Socrates to argue for many other doctrines as well.
In Socrates' discussion of injustice, we find a number of familiar themes: that there are experts in ethical matters and that one should not take just anyone's opinion as though it were of equal value, and that no one ever knowingly or willingly does wrong. However, at the same time, his equation of doing injury with injustice is again questionable. (Elsewhere, in the Gorgias, it is argued that an injury done to a wrongdoer in punishment is for the good of the wrongdoer.) Here, Socrates seems to be firm in his opinion that no injurious action can be just.