I'm not sure how many other fans of this excellent film realize that it's really an argument against determinism--in this case, biological determinism, but it could also be used as a valid refutation of environmental determinism. Father/murderer James Caan believes that since he himself is evil, and since his son's blood is the same as his, then his son Arlis (Dennis Quaid) must also have evil tendencies--as if Arlis is powerless to act otherwise. Arlis even buys into this nonsense: "It's not in your blood"; "If you're born to it..." He lives a solitary life, as if he's afraid that establishing a close relationship with someone would endanger them, because of the evil taint of his bloodline and his consequent evil potential--which isn't really there at all. But he realizes at the end that we all make our own decisions by means of our free will, and that our bloodline has nothing to do with that process. ("That's nothing. It's only blood.") Dostoevsky knew this too, when in CRIME AND PUNISHMENT or THE POSSESSED (I forget which) he shows how the revolutionaries of that era believed that "the environment" determines all human action--and he also saw how dangerous this idea is. The 20th century was a grim validation of his prophecies.
