" Sundiver " by David Brin, which was first published in 1980, is the first in the "Uplift" series of science fiction novels. It is that rare thing, a novel which thinks really big, asking huge questions about man's place in the universe and coming up with answers - true in the context of the novel - which are quite terrifying, yet it remains entertaining, accessible and easy to read, and manages to address issues of the ne3d to cherish our planet and environment without becoming in the slightest degree preachy. "Sundiver" is set in a world a few centuries from now, in a world where those who have been assessed by an exam as having a propensity to violence have been classed as "probationers," had a radio transmitter forcibly implanted in their bum so the state can track them. and deprived of most civil rights including the right to vote. It's also a world where human spaceships found "Eatees" (e.g. ETs, Extraterrestials) and w...