Thomas Aquinas can serve as a resource for conceptions of human happiness and practical reason that resist the flatness characteristic of Max U. While Aquinas shares with economists the notion that humans act in order to achieve desirable ends, and that their desire is infinite, he differs from economists in his understanding of the relationship between the finite goods we pursue in this life and the infinite good we desire. From a Thomistic perspective, we best pursue the infinite good not by accumulating an indefinite string of goods or experiences, but rather by ordering the finite goods in our lives well, seeking to reflect the infinite good, as in a mirror. The practical reason appropriate to such a project is prudence, which differs from Max U in its holism, its accent on discernment and deliberation, and its rejection of calculation in favor of ordering heterogeneous goods. Thomistic prudence thus avoids the flattening that is part and parcel of the Max U approach. Although Aquinas’s approach rests on metaphysical assumptions that are not universally held, engagement with his thought should help economists think through the extent to which the limitations of Max U depend on their own metaphysical assumptions.