Write every idea in a universal language of symbols, and fixed rules for calculating with them, which a machine could follow, will settle any question that doesn’t turn on facts about the world. Then such disputes can be settled without arguing: the two sides can sit down and calculate.
Every question of mathematics can be answered: there is no “we will not know.” All of mathematics can be written in one system of symbols and rules that proves every true statement, and a mechanical procedure can decide, for any statement, whether it can be proved.