"In the Green Machine there is no mercy; we make mercy, manufacture it in the parts that have overgrown our basic reptile brain.
There is no murder. We make murder, and it matters only to us.
Graham knew too well that he contained all the elements to make murder; perhaps mercy too.
He understood murder uncomfortably well, though.
He wondered if, in the great body of humankind, in the minds of men set on civilization, the vicious urges we control in ourselves and the dark instinctive knowledge of those urges function like the crippled virus the body arms against.
He wondered if old, awful urges are the virus that makes vaccine.
Yes, he had been wrong about Shiloh. Shiloh isn't haunted - men are haunted.
Shiloh doesn't care."
Graham in "Red Dragon" - Thomas Harris