The novel started with a man trying to escape a society where being psychic was illegal. He succeeds and sets up a ranch where he has a lot of children and no blue eyed children can leave. This goes on for generations until one child is born with blue spots in brown eyes whom is allowed to leave but who had the unique ability to resist the psychic powers of their sibling. Eventually that child spreads their genes to a space colony that goes about using their psychic abilities to prevent pain on nearby planets, but have a crisis of conscience over it, feeling they are preventing the other plants from experiencing life naturally and stunting their progress. They essentially end themselves all except for one who travels to one of the nearby worlds to help them adjust to the new experience of pain.
On that planet there was a coming of age ceremony she the child would choose fire or ice and the men would try to throw them into either the freezing cold outside or into a fire. Traditionally they would be physically unable to do so (when the psychics were preventing pain, they would be kind controlled to prevent the throw) by when the psychics stopped preventing pain, the comming of age ceremonies where ending tragically, especially if the child chose fire.
There was a theme to the book that in order to know true joy one must contrast it with pain