Monday, 15 February 2016
Logic is simply the consistency between propositions without which we would not succeed in saying anything. I find it necessary to say this because I have met people who think that logic has something to do with Mr Spock not having emotions or that a film featuring talking animals is "illogical" merely because talking animals are counter-factual in our experience.
If an sf future history series contains internal inconsistencies, e.g., in its chronology, then the narrative of the series is to that extent logically impossible. An Empire cannot have been founded four centuries before a given date and also have been founded three centuries before that date. The author can revise the texts or the inconsistency can be explained away, e.g., as an error on the part of a viewpoint character or the readers might just have to accept that the fallible author made a mistake.
A textual inconsistency is an aesthetic interference condition because it interferes with our aesthetic appreciation of the text. A visual equivalent would be a painting showing salmon swimming upstream at a time of year when they should have been swimming downstream.
A text that consistently contradicted itself would not present any intelligible narrative. However, no author ever says anything like, "Have I given several incompatible dates for a fictitious event? That is because I transcend logic and am not obliged to be consistent." So everyone does in fact accept the dreaded "logic" even if they do not realize it!