Distinctions on the common good, based on Pater Edmund Waldstein’s 37 Theses:
Private goods diminish when shared. Common goods do not diminish when shared.
Bread is a good, because it serves the human need for food. But if two people share one loaf of bread, they each only get half.
On the other hand, a joke is a common good which serves the human need for fellowship and social life. But when someone tells a joke, the enjoyment of the joke doesn’t diminish. It can be spread to many without being divided into smaller pieces.
Common goods are better than private goods.
A joke, however, is only a pleasant good. True common goods are honorable goods, things like peace, justice, and truth. When the truth is shared, it does not become less true. When peace is shared, it doesn’t get divided into pieces—every individual who shares in the common good enjoys total peace.
Because of this, common goods are obviously better than private goods. “It is honorable to attain a good for one man, but it is better and more godlike to attain a good in which many can share (cf. Nicomachean Ethics 1094b)” (Waldstein). Another difference is while private goods exist for our sake, we exist for the sake of the common good. Peace, truth, beauty, and goodness exist for their own sake.
The good of the individual is contained in the common good.
Some people worry that a politics of the common good will mean enslaving and abusing individuals for the “greater good.” This is the error of utilitarianism. The ends do not justify the means. It has often happened that “totalitarian regimes recognize the common good as a pretext for subjugating persons in the most ignoble way” (Charles De Koninck, On the Primacy of the Common Good, page 16). But this is a deceitful vision of the common good.
Rather, a true common good (peace, justice, etc) is good for each of the persons who partake of it—it is part of our individual good to serve the common good. This cannot be emphasized enough: the common good is a personal good. The subordination of persons to the common good is not slavery, but liberation.
As people become more virtuous, they seek more and more universal common goods.
Above we said that “it is part of our individual good to serve the common good.” This means that we cannot habitually act on our selfish desires if we want to serve the common good. Thus, the politics of the common good is also the politics of virtue. The common good will always be good for us, even though we might not enjoy it. Opulent wealth can be delightful for a greedy man. But it serves the common good for such wealth to be given to those in need. Peace and justice are objectively good for all, whether poor or rich. Only the politics of the common good can fulfill the purpose of law: to lead people to virtue.