One of the most influential books I've read is by David Lindsay. I believe it was published in the thirties, and called Voyage to Arcturus. It's a mind-expanding science-fiction novel, full of otherworldly occurrences with moral overtones. It's not perfect by any means, but it made a lasting impression on me.
Here's a poem I wrote long ago after reading the book:
to move
and live
and make
and love
close tones of of soul
to Crystalman with five primaries of two suns
and know (the growth change of green)
and have
and need
and hope
close tones of soil
to the fastest planetworth of jale
to think
of love
of light
the sheet of spectrum split
and bubbles run with rainbows
from the hoop
close tones of soul