Take a story's temperature by studying its tone. Is it hopeful? Cynical? Snarky? Playful?
Tone: Naturalistic
Don't let McCarthy's poetic language fool you. The guy describes his characters and setting like a scientist, almost always focusing on things that can be seen from the outside: behavior, statements, or appearances. It's very hard to find passages in this book where McCarthy says, "Character X thought such and such." Instead, we have to make judgments about people and places in this book based on what we can see as outside observers, just like in real life. The thing is, this is tough in this story because the characters aren't the type to lean on your shoulder and open up about their feelings.