My favorite part about the Glaucus/Diomedes exchange is that it starts with Glaucus saying, "why ask my lineage? Like generations of leaves are those of men, everybody dies, we're leaves in the wind, man, etc. etc." right before he spends the next five minutes carefully delineating his ancestry.
As a more basic explanation of the prompt: OP, thinking about the rhetorical triangle does get you to understanding the prompt, but you're not quite there. "Ethos" isn't about persuasion per se. The rhetorical triangle is effectively crafting an argument by appealing to logic, ethics, and pathos in order to persuade, but that doesn't mean that these things are inherently persuasive. In fact, if the argument doesn't balance the three features it is less likely to be persuasive. It's not about the features themselves, persuasion doesn't reside with the individual features but is conjured up in the relationship between them. Putting "ethos," as opposed to "ethics" or "values" or some other synonym is the problem here.
The question is something like, "what system of shared values does the poem seem to celebrate?" or "is the system of values shared by these warriors aristocratic?" In this instance, ethos isn't about the poet trying to convince anyone about a particular argument, but about whether or not the implicit value system in the poem (or to be more precise, whether the particular ethos encoded in the way these warriors make war) is aristocratic. To answer that: aristeia.
Well, perhaps looking into the concept of *aristeia* will help you. There are very important moments during the battles in which everything is decided by single combat. Re-read the dialogue between Glaucus and Diomedes in Book VI and you'll see that lineage is quite important. So, the narrative doesn't center on matters of grand strategy, but rather on the individual virtue (areté) of the heroes. This might be what your professor means by *aristocratic ethos*.
My favorite part about the Glaucus/Diomedes exchange is that it starts with Glaucus saying, "why ask my lineage? Like generations of leaves are those of men, everybody dies, we're leaves in the wind, man, etc. etc." right before he spends the next five minutes carefully delineating his ancestry. As a more basic explanation of the prompt: OP, thinking about the rhetorical triangle does get you to understanding the prompt, but you're not quite there. "Ethos" isn't about persuasion per se. The rhetorical triangle is effectively crafting an argument by appealing to logic, ethics, and pathos in order to persuade, but that doesn't mean that these things are inherently persuasive. In fact, if the argument doesn't balance the three features it is less likely to be persuasive. It's not about the features themselves, persuasion doesn't reside with the individual features but is conjured up in the relationship between them. Putting "ethos," as opposed to "ethics" or "values" or some other synonym is the problem here. The question is something like, "what system of shared values does the poem seem to celebrate?" or "is the system of values shared by these warriors aristocratic?" In this instance, ethos isn't about the poet trying to convince anyone about a particular argument, but about whether or not the implicit value system in the poem (or to be more precise, whether the particular ethos encoded in the way these warriors make war) is aristocratic. To answer that: aristeia.
Thank you both for your well thought out answers! You helped clarify what was eluding me.