I have been lurking for a few days, but I have a few thoughts I would
like to introduce respectfully into the discussion. Humans seem to have
a desire to believe that our perceptions can be separated into "facts" =
"absolute truth" and "beliefs" = "may be true." I am not so certain
that any of us can be that self critical. It depends on the standard of
proof you require.
The example of "all humans have a common ancestor" is an interesting
example but lacks clarity. The weight of scientific knowledge at this
point in time sides with evolutionary theory. Given that assumption,
your example may be true. There was probably a time when some people
believed that stars were holes in the sky. I doubt if all people
thought that. There probably even was some kind of theory advanced for
that belief. We "know" differently today. To redefine the example to
"all humans have a common human ancestor" is also problematic. It
assumes that there was a moment in time when our species was "not human"
followed by a moment when our species "became human." I am not entirely
certain that any of us are human yet… :0)
Marie