The Enemy

"The enemy was not, ultimately, other men, it was a universe never really meant for humanity, and you had conquered it when you understood it."
-Poul Anderson, Twilight World, 17, p. 168.

We have encountered the universe as enemy before. See Inner And Outer. If the universe is the real outer enemy, then mankind is his own inner enemy. See the search result for "protean enemy."

In Poul Anderson's Psychotechnic History, the Psychotechnic Institute struggles against the inner enemy whereas the Order of Planetary Engineers battles the outer enemy - while there also continues to be much conflict with and between groups of "other men." Anderson presents action-adventure fiction combined with social and philosophical reflection.