Two Themes In Wells, Stapledon, Lewis, Hoyle And Anderson

The previous post referred to one work each by Wells and Hoyle, two by Anderson and several by Stirling. Because of the reference to Hoyle's October The First Is Too Late, I have started to reread it. Hoyle makes the point that an sf alien should be something other than a human brain in a reptile body or even a humanoid body. Perhaps Anderson's Merseians or Ythrians measure up to Hoyle's criteria?

Alien Invasion
Wells and Stapledon: Martians invade Earth;
Stapledon: Earthmen invade Venus and Neptune;
Lewis: a demonically possessed scientist from Earth mounts a moral attack on the sinless Venus;
Hoyle: an intelligent gas cloud enters the Solar System;
Anderson: Martians conquer Earth but are controlled by extra-solars;
Anderson: militarily superior extra-solars conquer Earth economically.

Time 
Wells: The Time Machine;
Stapledon: mental time travel;
Lewis: an argument that physical time travel is impossible;
Hoyle: serious discussions of the significance of time and the meaning of consciousness;
Anderson: the Time Patrol etc.

Thus, a powerful tradition of serious speculative fiction.