If you can't reasonably prove a theory a priori, it's a very shaky theory.

( The Mock TurtIe ™ --- Thinks you are a cunt, on, Sat 5 Apr 2008, 15:32, archived)

I must be confused.
Surely you need evidence to prove a theory, and evidence is necessarily a posteriori?
( Bob Todd whee, Sat 5 Apr 2008, 15:35, archived)