“When ideas are in conflict, when truth is fighting against error, and revelation against human ingenuity, then there can be no compromise and no indulgence. If our Lord had exercised such indulgence, He would not have been crucified. When He called the Pharisees whited sepulchers and a brood of vipers, and Herod a fox, He was not inspired by any sort of hatred against individuals, but by the tremendous earnestness of truth. It was His defiant and vivid conviction of responsibility for eternal truth that caused Him to use such strong words towards error and its representatives. And if we do not fight thus for the truth, then we lose all moral and spiritual power, we become characterless, we disown God. Dogmatic intolerance is therefore a moral duty, a duty to the infinite truth and to truthfulness.”
-Karl Adam, The Spirit of Catholicism.