What Thomas Aquinas Teaches Us About Justice

by | Aug 11, 2026 | Opinion

The spines of old volumes of the Summa of Thomas Aquinas.
(Gabriella Clare Morino/Unsplash)

The ancient Greeks were quite concerned about justice in what they referred to as the polis—the city-state. Justice was one of the essential cardinal virtues, alongside wisdom, temperance, and courage. These virtues governed the activity of the soul, establishing the conditions for the mutual flourishing of all citizens in society.

Justice was a quintessential goal of all human activity. Human flourishing could only be realized, philosophers believed, when justice was enacted. Thomas Aquinas, who essentially “baptized” Aristotle’s virtue ethics model, provides a critical understanding of the justice needed in today’s fractured and divided society.

For Aquinas, the virtue of justice is chiefly concerned with the governance of human relationships and the mutual flourishing of all in society.  It is committed to providing each individual what they deserve in society. This requires a serious commitment to the well-being of others. Moreover, legal justice is principally concerned with governing human behavior as it relates to the common good of the community.

The virtue of justice does not focus on individual benefits but on the welfare of the community.

According to Aquinas, individuals in a community are essential parts of a whole.  Therefore, matters that affect one part of the community affect the whole. Things that are good or harmful for individuals are good or harmful for the whole community. Thus, community leaders should create laws that govern society in a manner that benefits the whole.  


For Aquinas, the quintessential reason for justice in society is to work toward the common good of all people.

In our own time, refusing to renew vital health care subsidies, while providing unprecedented tax breaks to millionaires and billionaires, has made health insurance unaffordable for millions. This does not support the common good of all citizens.

New work requirements and eligibility checks that make it more difficult for vulnerable citizens to have Medicaid coverage do not support the common good.

Policies that put caps on student loans for those seeking careers in nursing and healing professions do not support the common good. 


In a society plagued with division and partisan politics, we could benefit from a deeper understanding of what it means to embrace the common good, to work toward not only our own well-being, but the flourishing of all in society.

The ancient Greeks understood something vital about the activity of the soul and the activities that lead to the common good of all. Unfortunately, this wisdom is quickly vanishing from our modern view of the world. It is an understanding we cannot afford to lose.

Indeed, the prophetic witness of the scriptures still echoes through the airy stream:

He has told you, mortal one, what is good;
And what does the Lord require of you?
But to do justice, to love kindness,
And to walk humbly with your God (Micah 6:8).

So, let us go forth during these challenging times, working toward justice and the common good of all in society. For then we shall please the Triune God of creation and work towards the flourishing of all.