On McCarthy's 1985 anti-Western novel, featuring Wes, Seth, and Dylan.
How does violence play a role in the way the world works? The novel tells a historically based story of the 19th century Glanton gang who were hired as scalp hunters by the Mexican government but then went on a rogue massacre. It's told from the point of view of "The Kid," a 15-year-old member of the gang through its last stand at Yuma. It's filled with rich, often Biblical imagery and is pretty much a trippy orgy of violence.
So what's the philosophical interest? Well, the character of Judge Holden voices a lot of philosophy about destiny. His thesis is that the way to truly have agency in the world is through violence, not through morality (per Kant). Contra Nietzsche, the Judge does not see us as potentially transcending to a new greatness, but as on our way inexorably down. This book is a counter-narrative to American stories of Manifest Destiny that see a whole world of possibility open to our enterprising way of life. It instead seems to consider violence as inherent and central to the human condition (whether or not you as an individual may be isolated from it): The gang is opportunistic and short-sighted as it is driven (mostly) westward by its violent internal logic. The Judge sees violence as the only way to attain self-knowledge, to be truly honest with ourselves. Violence is the way that nations are established and enables bubbles of peace in which moral norms are accepted.