> humans cannot be sure that what they know IS the underlaying reality We can define the 'underlying reality" as the intersection of all people's beliefs, and

> humans cannot be sure that what they know IS the underlaying reality We can define the 'underlying reality" as the intersection of all people's beliefs, and what weight we give to each such belief. I don't know what it means to say something "is the underlying reality" or not. But we can give a definition to the term "underlying reality" and then talk about it.