R. Star wrote:
The canon is just the main, ongoing story being told by the original creators or their direct inheritors
So Gene Roddenberry's novelization of TMP or Jeri Taylor's novels are canon by that definition? Taylor has implied her novels are, others implied they weren't... and it goes on.
I said the main
ongoing story. The Motion Picture
itself was the main story; the novelization was an interpretation of that story. Thus TMP was the canon and the novelization was secondary.
As for Mosaic
, Jeri Taylor did indeed intend it to be canonical while she was the showrunner, and she referenced it in "Coda." But her successors decided that her novels were not to be treated as canon. It's easy to define canon when only one creator is involved; for instance, Sherlock Holmes fiction by Sir Arthur Conan Doyle is canonical, while that by other authors is apocryphal. The Del Rey Babylon 5
novels or the Buffy
Season 8-9 comics are part of their series' canons because their creators personally oversee them and choose them as the medium for telling a continuation of the core story. But with Trek, it's more complicated because the responsibility passes from one hand to another.
But as I said, canons are mutable. Fans are wrong to use "canon" to mean "right" or "real" or "consistent," because any long-running canon contradicts itself over time. A canon is a story being made up on the go, and that makes it subject to adjustment and revision. What is "real" in canon is whatever the current
interpretation is. Think of it as successive approximations. If the storyteller is trying to approach some Platonic ideal of what the "real" story is, they may make mistakes early on but then home in on it better as they continue. See my above comments -- it took TOS the better part of a season to get such basic concepts as the Federation and Starfleet settled on. The later ideas superseded the earlier, rougher ones.