Ideas And Their Implications

In sf, an author presents an idea together with at least one plausible but preferably unexpected implication of that idea, then other authors find other implications of the same idea.

One Wellsian idea: "time traveling."

Implications
(i) In Wells' "The Chronic Argonauts," circular causality. See here.

(ii) In Wells' The Time Machine, the Time Traveler returns to 1895 with an account of the ultimate fates of civilization and of life on Earth.

(iii) In L. Sprague de Camp's Lest Darkness Fall, an unwilling time traveler deliberately changes history.

(iv) In Ward Moore's Bring The Jubilee, a time traveling historian unintentionally changes history.

(v) In Poul Anderson's Time Patrol series, the Patrol, founded by our evolutionary successors, prevents accidental or deliberate changes to history, sometimes by completing causal circles.

Thus, readers recognize old ideas but welcome new implications and, in the above list, the Time Patrol synthesizes the four earlier stages.

Brian Aldiss' Galaxies Like Grains Of Sand presents some ideas that we have encountered in different works by Poul Anderson:

people immersed in virtual realities;
time travel;
one robots story in the future history;
a robotic ecology;
a reference to a generation ship;
the ancient ape in modern man;
reality as a shadow show.

Aldiss' distinctive contribution is a particularly literary style of writing, e.g.:

"Time unrolled itself like a long carpet, down which man ambled towards extinction."
-Brian Aldiss, "All The World's Tears" IN Aldiss, Galaxies Like Grains Of Sand (London, 1979), pp. 37-49 AT p. 38.