I know people who go back and check themselves, but it drives me crazy. Everybody wants to look in the mirror and see Cary Grant looking back at them, but that's just not the case.
Indeed, if a chief question does remain: how is the power to think possible? - The power to think right and left, before and without, with and above experience? then it does not take a deduction to prove the genealogical priority of language.
Sooner or later you must move down an unknown road that leads beyond the range of the imagination, and the only certainty is that the trip has to be made.