Nightfall= postmodern Genius.
overall I'd say immortality sounds like a hoot-
cue Devils advocate.
have any of you ever noted the mental state of those in our culture over the age of 80? yes? they are mostly nutbars. this mainly is due to innactivity- and in my opinion senility is our own stupid fault- Geronimo lived to about 86 and was always a sharp old fox.
Assuming the consensus version of immortality includes eternal youth, you have strength and motive (fighting the infernal boredom) to carry out the things that your subconcious mind has only fantasised about- Murder, Rape etc.
after a few millennia I'd be willing to try just about anything,
Immortality would breed, alongside complete mental degeneration, supreme capacity for learning, want to make a bomb? do insane people knit jumpers?
Immortal man would be a danger to entire human race.
'curiosity killed the cat, the immortal cat killed curiosity'
I am a cat, we are all cats.