could you clairify the following: what is an example of a primary problem? what is an example of a secondary problem? what is failure by your definition? what state would a problem be in if it were "solved"? is a problem solved when everybody agrees on a solution? what, then, happens when a contrarian states otherwise? e.g. parmenides was one of the first monists, and that was more or less not acknowledged for a long time after plato, but has since come back into vogue somewhat; was the problem of "is our universe one" solved, and then unsolved?