How large was mankind’s sense of obligation? The caveman first had this feeling for his mate, then for his family. It grew until men fought and died … - Harry Harrison

Just because you know a thing is true in theory, doesn't make it true in fact. The barbaric religions of primitive worlds hold not a germ of scientific fact, though they claim to explain all. Yet if one of these savages has all the logical ground for his beliefs taken away — he doesn't stop believing. He then calls his mistaken beliefs 'faith' because he knows they are right. And he knows they are right because he has faith. This is an unbreakable circle of false logic that can't be touched. In reality, it is plain mental inertia. A case of thinking 'what always was' will also 'always be.' And not wanting to blast the thinking patterns out of the old rut.

A kiss is a contact, a union, an exchange. It is unknown to certain races and tribes, while others know it and consider it with disgust. They all suffer a loss. A kiss can be a cold formula, or a token of familial relationship or a prelude to the act of love. It can also be a revelation in an unspoken, secret language of feelings that have never been expressed in words.

The human race is gregarious, I knew that even though I had been denying it for years. I was going to keep on doing the loneliest job in the universe — only I wasn't going to be doing it alone.