Such a statement can't be proven.

Sure, just append "unless it turns out we were wrong" to every scientific and mathematical claim if it helps you feel better.

I only append that to philosophical claims and string theory.

"philosophical claims and string theory" sounds redundant to me

Interesting. I can point you to some very influential philosophers who argue that not only can such an entity exist, it necessarily exists.

Can you tell me more about why you think it can't?

Apparently many other influential philosophers disagree, so take that proof with a grain of salt. https://en.wikipedia.org/wiki/Trademark_argument#Criticisms_...