This is the discussion where Socrates explains his willingness to accept his sentence at the hands of the state (Socrates was sentenced to death for the corruption of the youth – his teachings became frowned upon). It is a question of the legal judgements within the city having force. If an individual nullifies or invalidates the laws of the city, the city will cease to exist as a form of coherent governance.
First of all Socrates puts forward that one optional position to take is to claim that he has been treated unjustly, as his case has not been judged correctly. The point that Socrates now struggles with is that up until this point, by living in the city for an entire lifetime, he has really been in a contract with the city that its laws and customs are acceptable to him. He has agreed up until this point to abide by whatever judgements the city renders. Plato articulates the argument in a way that places all matters of judgement and custom together in a coherent system. If Socrates is to call into question this particular judgement at this stage, he is also to call into being a complaint against the marriage regulators who married his parents, who in turn brought him into existence i.e. if the state has guarded/shepherded/nursed Socrates family/existence/culture/language etc into being and Socrates has thus accepted these institutions, then he has no right to ‘destroy’ them now simply because they are not in his favor. In addition, the state of Athens also allows an adult to leave and take his property with him. Therefore, all adults are consenting in the laws and customs of the city:
“And thus we claim that anyone who fails to obey is guilty on three counts: he disobeys us as his parents; he disobeys those who nurtured him; and after agreeing to obey us he neither obeys nor persuades us if we are doing anything amiss, even though we offer him a choice, and do not harshly insist that he must do whatever we command. Instead we give him two options: he must either persuade us or else do as we say; yet he does neither.” (Plato in Annas, p381; Crito 52a)
A bit of exposition reveals that Socrates actually passed up his opportunity to defend himself against his death sentence, though in the context of this dialogue is attempting to think through the justification for escape for the benefit of Crito’s concern. With regard to the state authority described above, opportunity for defense is part of the equation.