Larry Sanger wrote:
What's "unhelpful" about it? I find unexplained and unfair criticisms unhelpful. Suppose the text said instead, as you say here, "Mars is a massive object that orbits the Sun." That's something that virtually everyone now agrees upon; therefore, according to the definition in the text it is a "fact" (something that we would all acknowledge to be fact, rather than opinion). What difference does it make that it was not a "fact," in this sense, five hundred years ago? The text explicitly acknowledges that "facts" can actually be falsehoods and "opinions" can be true, and that "facts" can change. Is there something *wrong* with that state of affairs, and do you think there's anything we can do about it?
It has never been and certainly is not a *fact*, by the definition given on the page, that God exists. The text actually explicitly uses that proposition as a prime example of an opinion.
I think you have a philosophic way of looking at this that other wikipedians may not share. I would be inclined to say "Mars is a planet" has *always* been a fact -- though at one time it was not *known*. If next year we discover that Mars is made of green cheese, then that too will have always been a fact -- and things that we currently hold as facts about Mars will be shown to be wrong.
(though that's the mathematician side of me -- things are still true even when you're not looking at them ;-) -- I do see Larry's point, just trying to highlight possible communication problems.
I think NPOV is sometimes abused, when articles on controversial topics degenerate into a list of every single possible opinion, with things like "Christian views on X" spiralling off.