The boy lifted the [flare]gun from the case and held it. Can you shoot somebody with it? he said.
[The Man:] You could.
[The Boy:] Would it kill them?
[The Man:] No. But it might set them on fire.
[The Boy:] Is that why you got it?
[The Man:] Yes.
[The Boy:] Because there's nobody to signal to. Is there?
[The Man:] No. (333.14-333.21)
McCarthy gives us a good dose of irony here. (Take it, reader! It's good for you!) Instead of using the flare gun to signal other people, The Man figures he'll use it to set them on fire. As if the only form of communication left on the planet is violence. So a tool typically used to signal distress becomes a grisly weapon.
He [The Boy] sat there cowled in the blanket. After a while he looked up. Are we still the good guys? he said.
[The Man:] Yes. We're still the good guys.
[The Boy:] And we always will be.
[The Man:] Yes. We always will be.
[The Boy:] Okay. (120.7-120.11)
This exchange happens pretty soon after The Man had to kill the roadrat. The Boy wants to know if they're still "good guys" after killing someone. Despite his doubts earlier that morning, The Man thinks they are still "good guys." We agree. But we also think McCarthy plays around with his terms here. There are actually no "good guys" in the strictest, most traditional sense. There are just the "sometimes-morally-compromised-but-mostly-good guys."
An army in tennis shoes, tramping. Carrying three-foot lengths of pipe with leather wrappings. [. . .] The phalanx following carried spears or lances tasseled with ribbons, the long blades hammered out of trucksprings in some crude forge upcountry. [. . .] Behind them came wagons drawn by slaves in harness and piled with goods of war and after that the women, perhaps a dozen in number, some of them pregnant, and lastly a supplementary consort of catamites illcothed against the cold and fitted in dogcollars and yoked each to each. All passed on. They lay listening.
[The Boy:] Are they gone, Papa?
[The Man:] Yes, they're gone.
[The Boy:] Did you see them?
[The Man:] Yes.
[The Boy:] Were they the bad guys?
[The Man:] Yes, they were the bad guys. (141.4-141.10)
It seems like another giveaway of the "bad guys" is that they keep slaves with them. The Man and The Boy, on the other hand, spend a lot of energy trying not to harm others. We think good and evil in this book have a lot to do with how one responds to desperate situations: do you prey on those weaker than yourself, or do you avoid others and try to retain some sliver of decency like The Man? Or, like The Boy, do you go above and beyond the call of duty and care for those worse off than yourself? We think the gap between this bloodcult on the road and The Boy seems nearly unbridgeable.