mousethief: "Lots of things exist that nobody has proven yet. If they didn't exist you couldn't prove them."

ummm... how about "Lots of things may exist that nobody has..."...etc.

And the 2nd part is a tautology that tends to suggest that 'because you haven't proved them yet, they probably exist'.
I am not being facetious...I have heard essentially this argument made.
It is SO easy to make a mis-step on the slippery slope of our own language and begin embedding assumptions of the sort.. 'if we have words for it, it kinda validates its existence'.