Friday, 27 June 2014
James Blish's four "pantropy" stories, collected as The Seedling Stars;
Poul Anderson's four post-Terran Empire stories, collected in The Long Night and again in Flandry's Legacy.
Both these tetralogies are hard sf with interstellar themes:
Blish's theme is artificial adaptation of human beings to extraterrestrial environments;
Anderson's theme is natural adaptations by human beings left isolated in extraterrestrial environments.
When I had explicitated this comparison, I realized why I had been thinking of these two series in parallel.
The pantropy series is a short but complete future history, covering:
an early interplanetary period;
intermediate periods on two extrasolar planets;
longer term galactic hegemony for humanity in its many adapted forms.
The post-Empire stories also cover a future historical period:
post-Imperial anarchy in the mid-fourth millennium;
an intermediate period while the Allied Planets restore interstellar civilization;
longer term, human civilizations have spread through several spiral arms and one is served by the Commonalty.
The main difference is that the post-Empire stories are not complete in themselves but are merely the concluding section of the much longer History of Technic Civilization.