An SF story is a story built around human beings, with a human problem and a human solution, which would not have happened at all without its scientific content. What made SF what it is today is incest and cannibalism. There is more room in inner space than in outer space. I know good through the study of evil. Evil can't be filtered out.
Fear is a survival instinct.
There's a chain of solid, unassailable logic in the things we do. The mind makes us do funny things. Some of them seem completely reasonless, wrong, insane. Sometimes the world's too much to live with and a body sort of has to turn away from it to rest. Logic and truth are two very different things, but they often look the same to the mind that's performing the logic.