If, as Milan Kundera claims, the purpose of the novel is to explore and expand the territory of living-in-the-world, then the purpose of the science-fiction novel must be even more far-reaching: to explore and expand living-in-the-world through the lens of a credibly fabricated future extrapolated from the present.
So: Imagine interstellar travel as powered by a vegetable junkie's experience of orgasmic nirvana. While thousands lie in suspended animation, the rich and their entourage live it up in a haze of hedonistic excess that you or I can only dream of. Once a day, the crew dumps a few numbers into the computer, the captain presses a button, and the ship instantaneously jumps a few light years ahead. No one knows what happens if the button is pressed without the numbers input, because no one's ever returned to tell the tale.
The Void Captain's Tale is many things: a tragic love story simultaneously
enabled and doomed by technology; a tale of obsessive madness, of a mind taken
over by a totalitarian idea of the absolute; a radical deconstruction of gender
politics and the purpose of society nestled within the struggle to break free
of maya and achieve nirvana. Above all, it's the work of a respected master,
arguably at the height of his powers--a finely crafted sci-fi milieu built up
from the very language it uses to describe itself, in which the largest
possible questions of conscious existence are explored and expanded. It's out
of print, but if you ever come across a copy, buy and read it. You'll be glad