After Laches gives his retort to Nicias, Lysimachus asks Socrates to break the tie between the two generals and decide whether the boys should or should not be instructed in the art of fighting with armor. To this question, Socrates merely asks Lysimachus if Lysimachus is prepared to just accept the opinion of someone who may not be an expert. Socrates then poses the same question to Melesias. Melelias replies that he would follow the advice of the one who had been trained and that his vote would be worth more than all four of the other men present, the majority. Socrates confirms that this is because a good decision is not based upon numbers but is based upon knowledge. Socrates then asks if there is any one among them who is an expert in the thing that they are deliberating. If there is then they will ask that person. If there is no one present who is an expert in the thing they are deliberating then they will seek further counsel. Socrates then emphasizes the importance of deciding whether one of them is an expert in the thing, which they are deliberating since it is their children's future, which is at stake.
Following this, Socrates imagines a situation in which he and his companions were trying to decide which one of them had the best knowledge of gymnastics. No doubt he says, that they would select the man who had learned and practiced the art of gymnastics and who had had the best teachers in the art. Socrates then asks whether they would ever have a question that would need to be addressed by the man's teachers. Melesias responds to this question with confusion about Socrates's meaning. Socrates then puts the point in a plainer fashion, stating that the men still haven't decided which art they are talking about when they ask which one of them is the expert in the thing they are deliberating. To this, Nicias replies that he believed they were deliberating about whether the young men ought to learn the art of fighting in armor. Socrates, however, claims that there is a prior question to this one and a prior area of expertise to that of fighting in armor.
Socrates proceeds to illustrate his point through various analogies. Socrates continues to state that when a person considers anything for the sake of another thing, he ought to think of the end and not of the means. Therefore, when you call in an adviser, you should see whether he too is skillful in the accomplishment of the end that you have in view. Socrates then says that the knowledge currently under investigation—the art of fighting—is only a means towards the end, which in Socrates's words is "the soul of youth." Therefore, Socrates concludes, they must decide which one among them if any is skillful or successful in the treatment of the soul and which one among them has had the best teachers in the treatment of the soul. Socrates proposes that he, Laches, and Nicias each tell Lysimachus and Melesias, what teachers they had in learning about the treatment of the soul. Whoever has had the most qualified teachers will be designated to counsel Lysimachus and Melesias concerning their children's training. But if none of them are deeded qualified based upon their teachers' credentials, Socrates suggests that they should not even try to give their own advice concerning the children since raising children is a very important responsibility.
This part of the dialogue begins with Socrates acting in a typically frustrating fashion by answering Lysimachus's question with his own. He criticizes Lysimachus's idea of breaking the tie between the two generals with his own by examining the case of gymnastics. It is clear in the case of gymnastics that the proper way of resolving the debate would be to ask the advice of an expert rather than going with the opinion of the majority. Socrates tries to demonstrate that they should take a similar approach in choosing one person among them qualified to make a decision about whether the boys should be taught the art of fighting in armor or not.
Socrates proceeds to emphasize the importance of finding exactly the right person to advise the education of the children due to the importance of the task. Socrates says, "Is this a trifle which you and Lysimachus have at stake? Are you not risking the greatest of your possessions? For children are your riches, and upon their turning our well or ill depends the whole order of their father's house." Plato must have seen the irony in the great care Socrates seems to show for the children's education in this passage. Since it was corruption of the young that Socrates was ultimately tried and convicted for, Plato must have meant to criticize the conviction itself or to redeem Socrates's reputation as a teacher. One may see this irony even starker in a later passage in this section. Socrates says, "We should not run the risk of spoiling the children of our friends, and thereby incurring the most formidable accusation which can be brought against anyone by those near him."
Having established that the future of the children of Lysimachus and Melesias ought to be decided by an expert, Socrates asks about the nature of the art of which they wish to find an expert. When Socrates asks the question, Nicias is confused for he believes that the art that they were discussing was obviously the art of fighting in armor. However, Socrates makes a distinction between what the men are doing and what an expert in the art of fighting with armor would be doing. Whereas an expert in the art of fighting with armor would be accomplishing the task of training the boys, Socrates and the other men are accomplishing no such task and therefore cannot be experts in the art form. It is the job of Socrates and the other men to select an appropriate path for the education of the children. In order to be qualified for that job, Socrates, or one of the other men must be an expert and have had good teachers in the art of instructing youth or the "treatment of the soul." Since the cultivation of the children's souls is the accomplished end of military training and the particular military training is only a means to an end, the advisors to the children must be experts in the soul rather than in the particular military training. Socrates's several analogies concerning eyes and horses serve to get this point across. Just as when we treat an eye with medicine we are concerned with the eyes and not with medicine for its own sake—and just as when we put a bridle on a horse we are concerned with the horse and not with the bridle itself—just so, since the men are looking for an advisor who will find a battle trainer to cultivate the boys' souls, they are concerned with the boys' souls rather than with a battle trainer.