Remember, it's not the baldness of the current King of France that's true or false, it's the existence of the current King of France.

I disagree. "the present King of France" is a definite description, like "the first man on the moon" or "the winner of the Kentucky Derby". These terms may or may not have referents but how are they true or false in the same sense as a statement / proposition such as "all humans are mortal"? But, mayhaps, true and false mean something else to you ...

Ceci n'est pas un seing.