Thus far we have analyzed different forms of moral relativism. While recognizing their strengths and that which they have to commend, we have seen that they do not align with the Catholic moral tradition because they are incapable of providing a suitable foundation for moral judgments and responsibility. What, then, is the foundation for Catholic ethics? The answer is twofold. On the one hand is revealed morality, accessible through faith. On the other hand is natural law morality, accessible through human reason. It is pivotal that one understands from the outset that the Catholic moral tradition has never understood faith and reason to be in competition with each other, nor has it regarded faith and reason as mutually exclusive.

There is a way of thinking called fideism, which holds that faith is inherently and inalterably irrational. In this view, faith propositions are necessarily absurd, and to try to make sense of them is to transmogrify them and waste one's time. There is another way of thinking called rationalism. According to this view, faith is all just make-believe and fairy tales and is, therefore, an obstacle to arriving at objective truth. Catholic teaching has never accepted either of these epistemological perspectives, but regards faith and reason as mutually informing and perfecting one another. Faith and reason are not like enemy soldiers on a battlefield. In the Catholic view, they are more like “two wings on which the human spirit rises to the contemplation of truth,” as stated by John Paul II in his encyclical letter Fides et ratio (faith and reason).