In a nutshell, Aquinas defined the common good as something that could be shared by all within a community without the good itself being diminished in any way. The purpose of the common good was to allow people to live a life of virtue that would lead to an increasing understanding and love of God. The purpose of law and government was to manifest the physical, social, and cultural conditions to make the living of virtuous lives and the union with God possible.
Though the Thomistic conception of the common good had its flaws and shortcomings, it was good in the sense that it did not seek to subordinate the spiritual to the material, but, rather, to organize the material world in a way that served to help individuals within communities attain salvation. Organizing the material world to mitigate temporal suffering and increase temporal joy was only justifiable if it maintained or increased the salvation of souls.
Traditional Christian social concepts like the common good were ordered around Divine love, which included the love of God, love of the self, and love of one's neighbor. The love within the Thomistic common good was directed at the divine essence of man; it was directed at concrete people and at certain spiritually valuable acts. Traditional definitions of the common good did not strive to create heaven on earth, but to create an earth that was more aligned with heaven, thereby increasing the potential for salvation.
This alignment of the material with the spiritual grew corrupted over time and went askew when human consciousness attained a level of spiritual autonomy. As freedom and agency increased, people began to reject the rigid Thomistic conceptualization of the common good and began subordinating the spiritual to the material.
In the early modern period, organizing the material world to mitigate temporal suffering and increase worldly joy became equated with salvation. Early charities and charitable work to help the poor and the sick beyond the scope churches contained a great deal of good and was still largely motivated by Christian virtues.
However, as these charitable activities expanded to include general notions of societal welfare and rights, they moved further away from their Divine origins and became more abstract in nature. For example, the Enlightenment emphasis on universal equality inspired abstractions such as the universal love of mankind.
Soon, material considerations usurped spiritual considerations altogether. Eventually, the universal love of humanity as a limited, earthly being eclipsed the Divine love of humanity as an unlimited, spiritual being. This quickly gave rise to the polemical social forces of leftism and its perpetual protests against Divine love.
Since modern interpretations of the common good rejected salvation altogether and were wholly aligned with material and humanitarian concerns, it set about attempting to create the very thing the Thomistic conception of the common good understood to be evil - heaven on earth. The results of these endeavors, culminating in an interpretation of the common good espoused by Marx, Engels, and twentieth-century communism, speak for themselves.
With the collapse of communism in Europe and the Soviet Union, the rallying cry for the common good became a mostly detached and passive feeling. Managing general welfare was left mostly to impersonal bureaucracies while individuals were encouraged to pursue mostly private goods. The pursuit of private goods was viewed as beneficial to the common good, particularly if private goods cohered with evolving global materialist interpretations of the common good, which had evolved into largely incomprehensible, incoherent, and contradictory abstractions of the grossest kind.
Throughout all of this, Christians succumbed to many false and evil interpretations of the common good; partly because the false and evil interpretations mimicked and inverted authentic interpretations of the common good as a spiritual movement and activity; and partly because Christians had lost all sense of the common good as a primarily spiritual movement and activity.
Though in itself good, the Thomistic vision of the common good faded as the consciousness of Westerners evolved toward freedom, self-determination, and agency. This evolved consciousness expanded general material welfare in a way traditional social teachings of the common good could not. At the same time, this expansion of material welfare uprooted the common good from its spiritual foundations and inverted it a means for worldly power.
From the perspective of consciousness, Westerners should have learned from these developments. They should have understood that purely materialist interpretations of the common good were inherently evil; and that these materialist interpretations could only be made good again if they were re-rooted in the Divine. This should have led to new understanding of the common good that included yet, at the same time, transcended traditional Christian social teachings.
None of this occurred. As a result, the Global Establishment and its System now have a monopoly on the common good in this time and place. This means that serious Christians must abandon all interest in the common good in this time and place.
To subscribe to or adhere to any aspect of the Global Establishment's vision of the common good is to subscribe to or adhere to opposition against God and Creation.
The common good the Global Establishment advertises is a complete inversion of the Thomistic idea of the common good. Not only does it aim to subordinate the material to the spiritual, it is also working to subordinate some aspects of the material against other aspects of the material. Within this paradigm, the world itself is valued more than the humans who inhabit it. In this sense, the Establishment's view of the common good is also anti-human - not just in the divine sense, but in the purely material sense as well.
The Establishment is currently organizing the world to condemn individuals an anti-spiritual life of decreased material welfare culminating in self-chosen damnation, all in the name of the common good. The Establishment is no longer interested in organizing the material world to mitigate temporal suffering and increase temporal joy in order to maintain or increase the damnation of souls - it seeks the mass damnation of souls through exacerbated temporal suffering and temporal joylessness.
The totalitarian forces that now rule the world under its banner of the common good is working to create conditions in which positive spiritual acts and movements become impossible, even at the level of individuals.
The only way forward for serious Christians is to return to an authentic vision of Christian love and the common good that focuses on the concrete and personal and rejects all abstract considerations of what is owed to collective totality.
This love begins with the love of the Divine - that is, the love for God and Creation - and encompasses a love of the self as a part of divine creation. From this divine self love, Christians can extend love to the neighbor - to the divine essence in actual, personal beings with whom they can form authentic spiritual relationships, with whom they can establish commonality and communion. Above all else, the core of this love is the maximization of soul salvation.
That is the only common good Christians should adhere to or consider in this time and place.