Our fundamental problem in finding the rational truth is not finding this truth itself, but in partitioning the world consistently and unambiguously. As soon as we have found out how to partition the world consistently and unambiguously, we can start searching the rational truth.
The problem with this problem is that it is not solvable, as Bertrand Russell demonstrated in 1901 with his paradox. We can thus not even get the tools we need to find the rational truth. Ain’t that an anticlimax for rationality as a religion?