The common good is both in itself and for us more lovable than the private good. But there could still remain a confusion, for one can love the common good in two ways. One can love it to possess it, and one can love it for its conservation and against its diffusion. In effect, one can say: I prefer the common good because its possession is for me a greater good. But this is not a love of the common good as common good. It is a love which identifies the common good with the good of the singular person considered as such. “To love the good of a city in order to appropriate it and possess it for oneself is not what the good political man does; for thus it is that the tyrant, too, loves the good of the city, in order to dominate it, which is to love oneself more than the city; in effect it is for himself that the tyrant desires this good, and not for the city. But to love the good of the city in order that it be conserved and defended, this is truly to love the city, and it is what the good political man does, even so that, in order to conserve or augment the good of the city, he exposes himself to the danger of death and neglects his private good.” And St. Thomas immediately applies this distinction to supernatural beatitude in which the notion of common good exists most perfectly: “Thus to love the good in which the blessed participate in order to acquire or possess it does not make man well disposed towards it, for the evil envy this good also; but to love it in itself, in order that it be conserved and spread, and so that nothing be done against it, this is what makes man well disposed to this society of the blessed; and this is what charity consists of, to love God for himself, and the neighbor who is capable of beatitude as oneself.” Hence one cannot love the common good without loving it in its capacity to be participated in by others. The fallen angels did not refuse the perfection of the good which was offered to them; they refused the fact of its being common, and they despised this community. If truly the good of their singular person should have been first, how could they have sinned against the common good? And most of all, how could the most naturally worthy rational creature fall away from the most divine good that exists?
A society constituted by persons who love their private good above the common good, or who identify the common good with the private good, is a society not of free men, but of tyrants—”and thus the entire people becomes like one tyrant”—who lead each other by force, in which the ultimate head is no one other than the most clever and strong among the tyrants, the subjects being merely frustrated tyrants. This refusal of the common good proceeds, at root, from mistrust and contempt of persons.
– Charles De Koninck, The Primacy of the Common Good Against the Personalists. (Available in a slightly different translation in 2 The Writings of Charles De Koninck 63, 79–80 [1943; McInerny ed., 2008].)