The various posts on this subject got me thinking about this question. Maybe absolute proof does NOT exist. And maybe that’s why the Torah warns us so vehemently to maintain the memory of Maamad Har Sinai by passing it from father to son and Rebbe to talmid.
My father told me that his he heard from his father who in turn heard from his and he from his and so on …and this actually goes back unbroken for 3000 years or so that the events in the Torah actually happened and that we met Hashem at Har Sinai, heard Him speak personally and that he at the time commanded us to accept a written and oral Law that would be transmitted from generation to generation, starting with Moshe. That’s why I together with hundreds of thousands of other Jews believe in the Torah. This doesn’t necessarily PROVE it’s true. It’s just the basis for my belief.
Think about it – if every generation since Matan Torah had faithfully passed this on and if every generation had faithfully accepted that fact – there would be no need for proof ever. If someone breaks the chain of tradition – that’s their choice. Everyone has bechira. Who’s to say the Torah provided an alternative way of connecting with our Mesorah. If someone then fails to pass on the tradition or fails to accept it – it’s too bad. Maybe to reconnect then does require a leap of faith of sorts.
Granted, their are very strong pointers that make denying it close to irrational. Chazal and the Kuzari and others provide these pointers. But absolutely solid, incontrovertible proof? I am not sure.