As earlier observed in our discussion of Plato's Republic, in response to Socrates a powerful presentation was made by Thrasymachus of the view that “justice consists in the interests of the strong”. This was developed by Glaucon, reporting what he describes as the “common opinion” that justice is unpleasant in itself but is pursued for the rewards it might bring and in the hope of a good reputation. “What they say is”, he continued:

“Taste of both” here implies that the ultimate measure of goodness is our own “taste” or, in other words, what satisfies our desires. “According to nature a good thing” amounts to the claim that, against Plato's later position, desire as a measure of “goodness” is not merely a motivational feature of the class of tradespeople but is a feature of human nature in general. It is “natural” to all of us to understand “goodness” or “justice” in this way; in other words, we will find that this is what we all “really mean” by it if we are trying to discover its nature through a kind of dialogue.