The Left has always sought single, non-values-based explanations for human behavior.
The truth needs to explain why you are the way you are, why you did what you did.
I do not think psychoanalysis has a scientific basis. If we can't explain why a cockroach decides to turn left, how can we explain why a human being decides to do something?
It would be really worrying if, as a Darwinian, it was impossible to think of ways in which our behavior could be explained.
I think chalking up human behavior to evil lets us all off the hook too easily.
Unable to understand how or why the person we see behaves as he does, we attribute his behavior to a person we cannot see, whose behavior we cannot explain either but about whom we are not inclined to ask questions.
It's very juicy to twirl your mustache and figure out why people do the horrible things that they do. It's not just because they are evil, but because that's how they somehow explain the world to themselves and justify themselves. It's always interesting figuring out how that happens.
Many a scientist has patiently designed experiments for the purpose of substantiating his belief that animal operations are motivated by no purposes. He has perhaps spent his spare time in writing articles to prove that human beings are as other animals so that 'purpose' is a category irrelevant for the explanation of their bodily activities, his own activities included. Scientists animated by the purpose of proving that they are purposeless constitute an interesting subject for study.
