The purpose of law is to lead people to virtue and the common good. This is the measure of justice and the source of all true rights.
Aristotle states in the Nicomachean Ethics, that “the end of politics is the best of ends; and the main concern of politics is to engender a certain character in the citizens and to make them good and disposed to perform noble actions.” (1099b)
In the Summa Theologiae of St. Thomas Aquinas, St. Isidore is quoted as saying that “laws are enacted for no private profit, but for the common benefit of the citizens.” (I-II. Q90. A2. s.c.) Thomas also says that “the purpose of human law is to lead men to virtue, not suddenly, but gradually” (I-II. Q96. A2. ad. 2) and that “there is no virtue whose acts cannot be prescribed by the law” (I-II. Q96. A3. co.).
In modernity, because this politics of virtue and the common good has been suppressed by violence and propaganda, it has fallen to Catholic Social Teaching to uphold the truth of integralism. The Social Encyclicals of the Holy Fathers have constantly affirmed this tradition. For example, in Libertas § 9, Pope Leo XIII states that “human law, properly so called, consists [in], binding all citizens to work together for the attainment of the common end proposed to the community, and forbidding them to depart from this end, and, in so far as human law is in conformity with the dictates of nature, leading to what is good, and deterring from evil.”
St. Pope Paul VI states that “Political power… must have as its aim the achievement of the common good… it acts in such a way as to create, effectively and for the well-being of all, the conditions required for attaining man’s true and complete good, including his spiritual end. It always intervenes with care for justice and with devotion to the common good…” (Octogesima Adveniens § 46).
The opposite view comes from liberals, whether conservative or progressive, of all different kinds who agree that the purpose of law is to protect our “life, liberty [in other words, freedom], and pursuit of happiness.” They appear to disagree vehemently on the details, but the purpose of law lurking underneath their arguments is the same.
We can certainly agree that the protection of human life is central to justice, but the word “freedom” and the pursuit of “happiness” have both been completely redefined by liberalism. Liberals think that we have “freedom” and can pursue “happiness,” because the liberal governments of the world give us “rights” or “human rights.” Many governments constitutions lay out what “rights” citizens have and the United Nations published (in 1948) a “Universal Declaration of Human Rights.” Liberal errors about the meaning of freedom, however, lead to errors about the definition of “rights.” Such errors have been used throughout modernity to justify the outrageous evils of capitalism and the insanity of liberalism.