What counts as "canon"?

[Morthoron]

A vastly entertaining thread, but canon is hogwash (I am actually getting more and more liberal regarding Tolkien canon as I get older). Let me explain by way of a simple example:

Read a history of WWII by an English or American author. Then read one by a Japanese historian. Next, try reading a WWII history written in Soviet Russia, and then another in 'supposedly' Democratic Russia.

I will guarantee these histories, if not profoundly different in their attitudes and factual presentation, will have at least several significant differences of opinions regarding certain events.

Now, which one of these 'real world' histories should be considered 'canonical'?

I rest my case for the time being.

P.S. The only things I would consider non-canonical in a Tolkien sense are those points that the author rejected outright (Trotter in the Hobbit, The Gnomes as opposed to Noldor, date changes in edition revisions, etc.). As someone in this thread (or maybe it was elsewhere) said, one takes the vast compendium of Middle-earth in its entirety as a history, and just like 'real' history there is some data that is more dubious than other more factual information; ergo, bring a salt shaker for the occasional necessary pinch.