Plausibility and Consistency

2017 August 15

Note: I’m using “reader” in a wider sense to mean a reader, watcher, listener, etc.; something like “consumer of some presented narrative”.

It’s more important in scifi to have intraworld consistency rather than [world] plausibility. The reason for this, at least as far as I see things, is that we cannot stand inconsistency, moreso than almost anything else. It makes our sapien brain fussy, and thus is intolerable. It’s why hypocrisy is such a sin and why so many of our cognitive biases are engineered to keep inconsistency invisible to our conscious mind.

Plausibility is relative to our (the real) world and our understanding of the way things work in worlds similar to ours. The similarity relation here is an interesting, nuanced one, founded on our understanding: we can easily understand the consequences of technology that is not only implausible but physically impossible, so these worlds are close to ours in this sense. In fact, these worlds are more similar than many worlds (but not all—I’m just speaking generally here) where the laws of physics are apparently the same but people act a little oddly. For example, it’s more acceptable to have a story involving time travel (very implausible) than one involving some minor character using a time machine in a way that doesn’t seem natural to the reader (somewhat inconsistent).

Tied up in this is the idea of a consistent narrative. A narrative can be inconsistent in several ways…

Some (most?) consistency breaks are physical law violations, some are more subtle. One additional factor in play is what I am going to call apparency of consistency, which is—approximately—how likely the reader is to become aware of a consistency break. Really what is intolerable is not consistency but noticed consistency, as, hey, the unknown is pretty tolerable. This connects with the idea of fridge logic, and could be the difference between examples three and four above, depending on how noticeable the impossible drive is (for a given reader).

Anyway, despite all this I think that plausibility is still very much worth considering. First, it is true that the more intraconsistency there is and the more intricate it is, the less important plausibility becomes. But at the same time, there must be some floor beyond which it is pretty difficult for a human to relate to a story, no matter how consistent it is.

Second, plausibility is linked with arbitrariness. The world in question could be wholly internally consistent but very arbitrary-seeming, for instance a world like earth, but where all the males whose first names don’t start with ‘W’ become blind for sixteen and a half seconds when they end a sentence with a preposition.

Finally, for whatever this is worth, plausibility and consistency start intermingling when you consider things at a laws-of-physics level, but I think that’s a topic for another time.

Everything above I would call fairly uncontroversial and maybe downright obvious but I thought it would make it clearer for me to type it out. Let me know if you take issue with any of it, for sure.

(For the de facto authority, see Consistency on TV Tropes. Note what I call plausibility is basically what they term “external consistency”.)