Before the usual irate and/or frustrated responses to typical canon comments occur I'd like to start a discussion that actually talks about the real crux of the problem and why people have such disparate definitions of the word and how it applies, to Star Trek and really any other media property that spans multiple mediums and has multiple licenses issued to release entertainment with its name on it.
The way the word is applied to Star Trek is basically this "The only things in Star Trek canon are every episode of every live-action TV series and every movie (that was released by Paramount/CBS)" Thus excluding all novels, comics, the animated series, documentaries (i.e. Trekkies) etc. We understand this is correct and final and unchangeable. So let's get beyond our typical frustrations with the topic and discuss why and how that is the case given how the word canon is defined and why the typical arguments like "Well Star Wars considers some of its books to be apart of their canon, so why can't Star Trek?"
I see the problem as being that someone somewhere is trying to redefine the word 'canon' from property to property. Like 'canon' means one thing for Star Trek but another for Star Wars and possibly even another for say Marvel. This, to me, seems to be where the frustration stems. We insist that 'canon' means one thing, but we look at a comparable property (Star Wars) and it doesn't mean that there.
So I went to Merriam Webster's site and Dictionary.com for the specific definition of the word 'canon'. Obviously there are various religious definitions but the ones that pertain to this topic are as follows:
from Merriam Webster said:
3 b: the authentic works of a writer c: a sanctioned or accepted group or body of related works
from Dictionary.com said:
3.the body of rules, principles, or standards accepted as axiomatic and universally binding in a field of study or art
5. a standard; criterion
9. the works of an author that have been accepted as authentic
Given these I totally see the confusion, but I think that confusion can be explained.
Let's look first at the Merriam Webster definition 3b. Given this it would seem that canon for Star Trek would be only that which Gene Roddenberry himself wrote, which would then cut out the end of TNG, all of DS9, Voyager and Enterprise and most of the movies. But that's not right. Why? Because we're talking about Star Trek canon, not Gene Roddenberry canon. So this isn't the definition of the word we need.
Looking at Merriam Webster definition 3c. Even I have some confusion with this as it doesn't seem to hold up to how Star Trek defines its canon. I'm more than open to listening (and it's kinda the point of this whole post) to anyone with some good clarification to this, more than simply "it is what it is because TPTB say so." This to me means books could then be included in canon because they are officially sanctioned, accepted, and all clearly related. Now, to ease some of you all's initial cringe because I know how hot a topic and how frustrating it can be around here, let me make clear, I DO NOT by any means insist this must be or even is the case. I'm just relating that given that definition it would seem to make sense. I want the clarification that I'm sure someone can provide as to why it isn't.
Let's now look at dictionary.com's definitions which I think actually shed a touch more light on the subject. Definitions 3 and 5, makes it a little more clear and fits perfectly with Star Trek's definition. Being axiomatic and universally binding is exactly what Star Trek insists on. All tie-in material MUST be consistent with that which is in the TV series and the movies, but does not need to be consistent with anything else. Therefore that portion of the property that is the 'universally binding' criterion is the part that is canon, and therefore can actually be defined on a property by property basis. If Star Trek ever decided that they wanted to force all tie-in material to be consistent with some Star Trek book then that book would be canon. This even explains the confusion with the two Voyager books
Pathways and
Mosaic at one point someone might have made that decision, then when Jeri Taylor left someone else decided that wasn't the case anymore so for a while there those books were canon, but now they are not. New fiction that comes out does not need to be consistent with these books therefore these books are not canon.
Definition 9 is, of course the same as Merriam Webster's definition 3b.
Of course the other problem with the definition of canon is a lot of people's misconception that 'canon' is synonymous with the word 'continuity' and it isn't at all. This then inevitably spawns off discussions of what "actually happened" in a fictional universe vs what the creators of the universe consider to have "actually happened." Neither of those matter to a discussion of canon since canon itself can be out of sync continuity-wise and both continuities can still remain canon by definition.
Now, I realize my 'analysis,' if you will, of this has itself answered my previous question from Merriam Webster's 3C definition, but for the sake of argument and an actual good discussion of canon for a change, by all means if you have more to add, let's talk about it. Hopefully without the usual canon frustration and irate debate.