If for every rule there is an exception, then we have established that there
is an exception to every rule. If we accept "For every rule there is an
exception" as a rule, then we must conced that there may not be an exception
after all, since the rule states that there is always the possibility of
exception, and if we follow it to its logical end we must agree that there
can be an exception to the rule that for every rule there is an exception....