There are a number of good reasons for Hippocrates to blush when Socrates suggests that, because Hippocrates wants to study under Protagoras, he must therefore want to become a Sophist. Hippocrates is an aristocrat; sophistry was frowned upon by the Athenian aristocracy and considered to be a method of education that furthered the political ambitions of aspiring demagogues. To want to become a Sophist was indeed a disreputable desire for a young Athenian aristocrat. Hippocrates may also be embarrassed that he so clearly has no idea what he hopes to learn from Protagoras. Having roused Socrates early in the morning because he is so excited that Protagoras is in Athens, Hippocractes might well be ashamed that he lacks any firm conception of what Protagoras's presence in the city might mean, or what Protagoras has to offer him. He may well also be a little humiliated at how easily Socrates has exposed his ignorance.

But these answers all remain at the level of Hippocrates's psychology. The blush has a further significance within the argumentative structure of the dialogue. Hippocrates's response to Socrates's question is non-verbal. Asked what he hopes to learn from Protagoras, Hippocrates gives a corporeal answer, rather than communicating with words. Socrates places great emphasis in this dialogue on the importance of people defending their opinions in person. For him, a philosophical theory needs to be embodied in the habits and behavior of its holders for it to be genuinely philosophical. By blushing—a bodily reaction over which one has no control—Hippocrates responds completely to Socrates's probing questions. His desire for virtue is shown to be undeniable, even if he is not entirely sure how to attain his goal.

At the end of the Protagoras, Socrates declares that he and Protagoras have swapped positions during the course of the argument. Socrates says that he began by questioning whether virtue can be taught, but that he ends by asserting that virtue is knowledge, and therefore teachable. It would seem as if there were a contradiction here. However, another clear theme of the dialogue is the need to carefully consider whether apparent contradictions really hold. In his analysis of Simonides's poem, for instance, Socrates shows that what had seemed to be a contradiction was in fact a consistent attitude. Indeed, this apparent contradiction held the key to the true meaning of the poem. The difference between Socrates's original position and his final position is an analogous case. Consider what is meant by "virtue" at the start of the dialogue, and at the end. The entire dialogue is an analysis of the concept of virtue; by the end, we have a far better understanding of what it is to be virtuous than at the beginning. At the beginning, Socrates is operating with Protagoras's concept of virtue (virtue as it is represented in political decision-making, for instance). This concept of virtue still exists at the end of the dialogue, but it has been incorporated within a far more expansive idea of what constitutes virtue. Socrates has attempted to prove that all virtues are, in fact, one and the same virtue; courage, wisdom, temperance and so on are forms of knowledge. If this is so, then the types of virtue Protagoras has in mind at the start of the dialogue cannot be divorced from these more inherent aspects of a personality. Thus, virtue is indeed teachable, but not if it is considered only as a particular political function. The contradiction is merely apparent, not destructive to the argument.

In Protagoras's creation myth, the animals are awarded certain types of attributes peculiar to each species, so that the natural world forms a harmonious and unchanging system. But humans miss out on this distribution, and risk dying out because they are "unclothed, unshod, unbedded, unarmed" (321c). If the animals are by nature self-sufficient, humans are by nature inadequate. Our natural defenses cannot protect us from the hardships of the world. It is as if all humans are born prematurely, unable to cope biologically with the conditions of their existence. But this innate lack is satisfied by other human attributes: in order to preserve the existence of the human race, Protagoras states, the gods gave humans both the arts of acquiring food and shelter—farming, hunting, weaving, building, and so on—and the capacity to form communities. We can translate these symbolic and mythical elements into an abstract statement: what Protagoras asserts here is that it is culture that completes human existence. Without forms of culture— technologies, political systems, different professions and so on—humans cannot exist. But this entails a crucial difference between the natural world, which is static, and human society. In Protagoras's myth, humans are necessarily cultural beings; unlike animals, they are not determined by their biology. Thus, the world that humans inhabit can be changed by deliberate actions. The negative definition of humans in Protagoras's creation story therefore opens the space in which historical development can occur.