Living With Inconsistencies

Poul Anderson: 

"Perfect consistency is possible only to God himself, and a close study of scripture will show that he doesn't always make it." (1)
-copied from here.

Inconsistencies impossible in reality can occur in fiction. In a World War II series by Dennis Wheatley, Gregory Sallust's London apartment is destroyed by a bomb in an earlier volume but remains intact in a later volume. Sallust does not notice because he is in the story so his memory must have changed accordingly. On reflection, such discrepancies could occur in reality provided that our memories and all other evidence were to change as well. (Wheatley had the same interesting conservative politics as Dornford Yates and was an inspiration for Ian Fleming.)

In the eleventh of his twelve James Bond novels, Ian Fleming not only contradicts biographical information as given in the first volume but also ingeniously relegates the previous ten volumes to the status of inaccurate fictions within the fiction, written by a former friend and colleague of Commander Bond.

A prima facie contradiction in Poul Anderson's Dominic Flandry series is addressed here.

Yates' Mansel and Chandos: pre-War and between the Wars; individual criminals.
Sallust: World War II; the Gestapo.
Bond: the Cold War and its aftermath; SMERSH, then SPECTRE.
Flandry: the Terran Empire; Merseia.

Heroes and villains fiction is an endless cycle: each hero defeats successive individual villains, then is succeeded by another hero created by another author. For post-Bond fiction that tries to break out of this cycle, see:

Bond, UNCLE and The Prisoner 
007, No 6 and V

Reader Responses To Inconsistencies
(i) Some do not notice.
(ii) Some do not care: "It's only fiction."
(iii) Some care. Of course there can be different versions of a story but when either a single work or a series is presented to us as a coherent narrative, then it should be coherent. Inconsistency is an aesthetic interference condition like a painting showing a salmon leaping upstream when the color of the foliage in the background indicates that it is the season when the salmon should be leaping downstream. The Baker Street Irregulars find explanations for contradictions in the Holmes canon. We should do the same for Anderson, although he has less contradictions.