The common good is not arbitrary. It can be deduced from these three principles:
- “…human rights are protected and basic responsibilities are met”
- “… the dignity of work and protecting the rights of workers”
- “We have a duty to care for God’s creation”
Source for the above: “Forming consciences for Faithful Citizenship” by the USCCB.
I don’t think this is totally accurate. 2 and 3 simply fall under 1. I think the CCC gives the better list of the three essential elements:
CCC 1925 The common good consists of three essential elements: respect for and promotion of the fundamental rights of the person; prosperity, or the development of the spiritual and temporal goods of society; the peace and security of the group and of its members.
Blue Horizon:
And who decides if these worthy principles are met?
And if it’s just me then it’s not really common good anymore it seems!
This is ultimately the purpose of civil authority.
CCC 1898 Every human community needs an authority to govern it.16 The foundation of such authority lies in human nature. It is necessary for the unity of the state. Its role is to ensure as far as possible the common good of the society.
Pope Francis, Evangelii Gaudium: 240. It is the responsibility of the State to safeguard and promote the common good of society.
Pope St. John XXIII, Pacem in Terris: 54. The attainment of the common good is the sole reason for the existence of civil authorities.
Again, while we all have a role to play, it is primarily the job of civil authority:
CCC: 1906…The common good concerns the life of all. It calls for prudence from each, and even more from those who exercise the office of authority.
CCC: 1910 Each human community possesses a common good which permits it to be recognized as such; it is in the political community that its most complete realization is found. It is the role of the state to defend and promote the common good of civil society, its citizens, and intermediate bodies.
Furthermore, this can’t be arbitrary. The state must measure its judgments according to the truth.
CCC1902 Authority does not derive its moral legitimacy from itself. It must not behave in a despotic manner, but must act for the common good as a “moral force based on freedom and a sense of responsibility”:21
A human law has the character of law to the extent that it accords with right reason, and thus derives from the eternal law. Insofar as it falls short of right reason it is said to be an unjust law, and thus has not so much the nature of law as of a kind of violence.22
CCC1903 Authority is exercised legitimately only when it seeks the common good of the group concerned and if it employs morally licit means to attain it. If rulers were to enact unjust laws or take measures contrary to the moral order, such arrangements would not be binding in conscience. In such a case, "authority breaks down completely and results in shameful abuse."23
CCC 2244 Every institution is inspired, at least implicitly, by a vision of man and his destiny, from which it derives the point of reference for its judgment, its hierarchy of values, its line of conduct. Most societies have formed their institutions in the recognition of a certain preeminence of man over things. Only the divinely revealed religion has clearly recognized man’s origin and destiny in God, the Creator and Redeemer. The Church invites political authorities to measure their judgments and decisions against this inspired truth about God and man:
Societies not recognizing this vision or rejecting it in the name of their independence from God are brought to seek their criteria and goal in themselves or to borrow them from some ideology. Since they do not admit that one can defend an objective criterion of good and evil, they arrogate to themselves an explicit or implicit totalitarian power over man and his destiny, as history shows.51
Ultimately, the authorities must stand before God to account for their actions like we all must. So in that sense, He is the final judge. But in the meantime, we all must do our part to work toward the common good, especially the civil authorities. If they harm the common good we should vote them out of office.