Now, that lack of comprehension does not prove the non-existence of the plant!

I can't prove you're wrong any more than I can prove the non-existence of God!

Kurt could give his honest promise, for he had enough of his endeavour to prove the non-existence of the ghost.

Two hundred years ago-morethan that, even in his 'Essay concerning the Human Understanding,' he provedthenon-existence of innate ideas.