Socrates asks Menexenus if they may have been "altogether wrong" in their conclusions, considering the impasse at which they have now arrived. Lysis suddenly interrupts to say that surely this must be the case; he then blushes at this outburst, and Socrates notes that Lysis has been eagerly following the whole conversation. Socrates is pleased at this interest, and decides to let Menexenus rest for a moment and talk to Lysis again.

Socrates begins by agreeing with Lysis that the discussion went wrong somewhere, and turns to the poets ("the fathers and authors of wisdom") for a new start. Socrates recalls the poets saying that "God himself" creates friends and draws them together, as expressed in the verse, "God is ever drawing like towards like, and making them acquainted." The philosophers ("the people who go talking and writing about nature and the universe") also say that "like loves like."

Socrates points out, in passing, that the philosopher's saying doesn't really apply to bad people, who are just as likely to hate other bad people as anyone else. He conjectures, however, that this is because such people are at variance with themselves, and so cannot be in harmony with anyone else. The saying thus implies (in an riddling way) that good people are only friends with good people, and that bad people are friends of no one.

Thus, we can now answer the question, "who are friends?" The answer is simply that "the good are friends." This answer does not entirely satisfy Socrates. In explaining why, he begins with a few halting sentences to the effect that like cannot do any harm or good to like without being equally capable of doing that same harm or good to himself. If this is the case, how can either of the two be of any use to each other? And if they are of no use to each other, they cannot love each other, and so cannot be friends.

But what if, Socrates suggests, likeness itself is not the condition for friendship, but rather likeness-in-goodness: "the good may be the friend of the good insofar as he is good." Here, however, the same problem arises, in that he who is good is "sufficient for himself" exactly in as much as he is good, and so has no need for others on this basis. So again, without want and desire, there is no reason for friendship; friends must value each other for some reason.

Here Socrates suggests that he and his young interlocutors are again "entirely wrong," and quotes some moments from Hesiod that indicate that dissimilarity, not likeness, is the source of friendship. According to Hesiod, "the most like are most full of envy, strife, and hatred of one another," and everything values what is not like itself (as "the dry desires the moist, [and] the cold the hot."