Thomas Aquinas (1225 – 1274) is known for having successfully integrated Aristotle’s teaching with that he inherited from Platonism and Medieval Christianity. His work is thus a creative reappropriation of Aristotle’s in the context of a Christian worldview. The Scholasticism that was built on his system has become the foundation for mainstream Catholic philosophy into the contemporary period. My focus here will be on Aquinas’ virtue ethics and political thought.
Like Augustine, Aquinas emphasizes the value of human reasoning in addition to the value of revelation. Humans, he argues, have both natural and supra-natural goals. Our knowledge system thus should appeal to both; and the state should, as much as possible, facilitate the development of both our natural and spiritual natures. Though he, like Augustine, will maintain that we will reach our ultimate fulfillment only in the next life, he does think that it is part of God’s plan that justice be cultivated here and now.
One of the political teachings that Aquinas is best known for is his natural law theory. There are, according to Aquinas, four types of law, with the following general characteristics:
- Eternal law — This is the law of God’s unchanging reason. He reveals some of this to humans.
- Divine law — This is that part of God’s law that he reveals in the scriptural traditions and the oral traditions of the church.
- Natural law — This is the law that we can know, irrespective of our faith, in the light of reason. All rational individuals can divine this law.
- Human law — This is the existing legal order at a particular time and place.
Aquinas thinks that all human groups have some possibility to understand the natural law through reasoning processes. He draws in particular on the Aristotelian tradition, which impresses him for its thoroughness. But given this ability to reason, human groups form societies and regulate human behavior. Any political order should thus have some respect for the institutions that it finds in existence. The existing laws of any given place, however, might diverge from what the light of reason indicates they should be. So while political orders deserve some respect, a particular problem is that human groups might use reason badly. This means the human law might diverge from the ideal natural law. The state should work to ensure that the human law does not diverge.
For Aquinas, like Aristotle, the state exists for the flourishing of the human beings that comprise it. However, Aquinas also understands that flourishing somewhat differently than Aristotle. It requires meeting what Aristotle called the “external goods” — that is, the goods to meet our bodily needs — but it also requires a different set of “internal goods” than Aristotle had pointed to. In addition to the cardinal virtues highlighted in Ancient Greece — of wisdom, fortitude, moderation, and justice — Aquinas underlined Christian virtues of importance, namely faith, hope and love.
In Aquinas’ view, the divine law — the scripture and oral tradition of the church — serve to aid individuals in using their natural reason. Left to our own devices, Aquinas fears we will misuse reason. In deliberations, he thus thinks the state and individuals should be guided by their faith tradition. While Aquinas does emphasize the need for individuals to follow conscience, like many other Medievals, he thus also emphasizes the virtue of “obedience.” Conscience in his view must be exercised in consultation of views of the church.
Aquinas’ develops his moral thinking beyond the virtue ethics of Aristotle into a natural law theory. In the main his argument is that humans have natural purposes. Fulfilling these requires the following of traditional Christian moral norms. That overarching purpose is to fulfill our lives in grace with God. Our moral and political lives should facilitate that.
Aquinas is also known for having offered proofs for God’s existence. His famous five ways show what he thinks are the most promising avenues for demonstrating the rationality of the view that God exists. These proofs were not offered because of any threat of atheism in the Medieval world but in order to indicate that faith itself overlaps with rationality. In fact, the idea that faith and reason do not conflict becomes basic to Thomism and the Catholic worldview. This means essentially that Catholicism came to view itself as the most rational philosophy that exists. It completes the Greek philosophy, augmenting and complimenting it with an understanding of Christian revelation. The tradition emphasizes that all truth comes from God. Thus one cannot end up with two incommensurable worldviews, one underwritten by reasoning and science, the other underwritten by the Christian faith.
This is one reason that Catholic higher education to this day emphasizes the need for education in philosophy and highlights the importance of the natural reasoning in the sciences. In the standard views of the church: Reason prevents faith from falling into superstition while faith prevents reason from falling into reductionistic views of human understanding.
This is one reason that Catholic theologians in the contemporary world tend to underline the truth of science and, for example, offer metaphorical rather than literal readings of the creation narratives of the bible and underline evolutionary theory. Historically, however, while the Catholic church has maintained the complementary nature of faith and reason, they have often enough failed to support scientific developments, and emphasized instead traditionalist readings of scriptures. The Galileo case is one of the most prominent in its history. Here, rather than taking the side of the leading advocates of science, it censored them. Over time it came to regret that decision.
The view of the Thomistic tradition that faith and reason do not conflict continues to have an intellectual appeal for many religious. Mainstream philosophers, however, tend to question whether such a conflict can be denied in light of the continued insistence of the church on the literal truth of the miracles in the bible, and the beliefs in the immaculate conception, the ascension of Mary and Jesus into heaven, the belief in transubstantiation and so on.
The Thomistic tradition, for its part, offers arguments for God’s existence that it deems as successful and then maintains that if God is all-powerful, such supernatural events as just mentioned would be within his power. Mainstream philosophers of the 21st century largely see such arguments as straining credulity.
For more on the general history of ideas after Aquinas, the Transition to the Modern World