The difference between truth and fiction is that fiction has to make sense

There was an amusing aphorism about truth and fiction in the new movie The International (with Clive Owen and Naomi Watts.) I may not have the exact wording, but it is roughly:

The difference between truth and fiction is that fiction has to make sense.

(Or maybe it was "There is a difference between truth and fiction -- fiction has to make sense.")

That sounded like it was probably a noteworthy quote from somebody, so I did a Google search. Mark Twain's name popped up a few times with various wordings. I did another search using his name and found these two quotes on BrainyQuote.com, so they are probably the definitive quotes:

It's no wonder that truth is stranger than fiction. Fiction has to make sense.

Why shouldn't truth be stranger than fiction? Fiction, after all, has to make sense.

A similar quote is attributed to Rosten, Leo:

Truth is stranger than fiction; fiction has to make sense.

And a similar quote is attributed to Tom Clancy:

The difference between fiction and reality? Fiction has to make sense.

My suspicion is that the film used Clancy's version. If I ever meet Clancy, I'll ask if he "borrowed" from Twain's adage.

Finally, Alex Lane asserts that Twain's adage is "roundly refuted" by the popularity of The X-Files.

So, can we use the fact that a proposition "makes sense" as a criteria for judging truth or lie, fact or fiction? If not, what good is it for us to obsess over whether anything "makes sense"?

-- Jack Krupansky