The cardinal virtues did not come from cardinals. They predate Christianity. Cardinal derives from the Latin root cardo, meaning hinge, principal, or chief. Hence principal priests became cardinals. Similarly certain chief virtues, first enumerated by Plato, were called cardinal when they were included in Christian teaching. Crucially Thomas Aquinas, who thought reason and faith were complementary, made a distinction between virtues that were natural versus supernatural. He declared the four cardinal virtues -- temperance, prudence, courage and justice -- as natural, and the three theological virtues -- faith, hope and charity -- as supernatural. Those natural virtues had long been rationally understood to be needed to live well. They encode and encourage what we could call in modern terms adaptive behaviors or useful survival skills. Even for Aquinas they weren't about the afterlife, they were habits needed for a better after-in-life. - www.huffingtonpost.com