Robert B. Parker said this quote
“ See, being a person is kind of random and arbitrary business. You may have noticed that. And you need to believe in something to keep it from being too random and arbitrary to handle. Some people take religion, or success, or patriotism, or family, but for a lot of guys those things don't work. A guy like me. I don't have religion or family that sort of thing. So you accept some system of order, and you stick to it. ”