Originally Posted by GA Russell
I nominate The Brothers Karamazov by Fyodor Dostoevsky.
Amazon says: Dostoevsky's last and greatest novel, The Karamazov Brothers (1880) is both a brilliantly told crime story and a passionate philosophical debate. The dissolute landowner Fyodor Pavlovich Karamazov is murdered; his sons--the atheist intellectual Ivan, the hot-blooded Dmitry, and the saintly novice Alyosha--are all involved at some level. Brilliantly bound up with this psychological drama is Dostoevsky's intense and disturbing exploration of many deeply felt ideas about the existence of God, freedom of will, the collective nature of guilt, and the disastrous consequences of rationalism.