This is a silly notion.
I believe that G-d gave the Torah to Moses, and Moses gave the Torah to the nation of Israel. This is an article of faith that Jews repeat every time (well almost) the Torah is read publicly.
Is it really true that this cannot be disproved?
Couldn't evidence turn up somewhere in a sort of anti-Josephus tome that depicts the entire history of the near-east in a completely different fashion; and then some more evidence that shows that the Torah was created sometime around the time of Jesus; or maybe by Jesus himself; and then maybe more evidence that forces most reasonable people to conclude that Moses is a fiction? I don't expect any of this to happen. Maybe that's faith. But there is some reason mixed in with it all.
ML/NJ
A primitive faith or even elements of a sophisticated one have contradictory evidence, but AFAIK, no major faith is ever “disproved”. Debating faith may be educational, but resolves nothing.