Thomas Aquinas


Distinguished medieval theologian and philosopher
Born in the town of Aquino (Italy), about eighty miles southeast of Rome, Aquinas had a large physique which earned him the nickname “dumb ox.” His combination of theological learning and Christian devotion, however, later earned him the label “angelic doctor.” Educated at the Universities of Naples, Paris, and Cologne, he belonged to the Dominican order of preachers. He taught in Paris, Rome, and elsewhere, and provided the Dominicans with both theological and organizational leadership. The traditional theologians of his day so distrusted his use of Aristotelian philosophy that some of his teachings were condemned by the church for about fifty years. But his cause soon became that of the whole Dominican order, with the result that they adopted his theology (known as “Thomism”), whereas the Franciscans followed instead the teachings of Bonaventure and Duns Scotus.
In 1879 an encyclical of Pope Leo XIII, Aeterni Patris, precipitated a major revival of Thomistic influence in the Roman church by calling for a return to Aquinas’s teaching to combat the modernism and agnosticism of that day. Thus, various Thomistic schools grew up, dominating Roman Catholic theology and philosophy until the 1960s, when Aquinas’s authority was moderated by the influence of phenomenology and of European biblical theology. Although Thomism is not the official Catholic position, Aquinas is held in the highest respect, is diligently studied, and has had a profoundly stabilizing effect on Catholic thought through the centuries.
Protestant appraisals vary. Some Protestants are themselves Thomists. Lutheran and Reformed theologians tend in other directions—Lutherans being closer to William of Ockham’s nominalism and Reformed thinkers to John Calvin. Aquinas is criticized because he attempted a synthesis of Aristotelian philosophy and biblical theology which, in the judgment of some, compromised such doctrines as the sovereignty of God and the total depravity of man.
Central in Protestant discontent is Aquinas’s perception of the relation between philosophy and theology, and of the role of reason in each. Philosophy, he maintained, is the servant of theology, which is taken as the “queen of the sciences.” Philosophy establishes what theology assumes, the existence of God and the immortality of the soul. But the philosophical attitude is religiously neutral in that its premises are universally accessible truths about nature, such as Aristotelian science provided, and its method is strictly logical and argumentative, rather than depending on biblical revelation. The “autonomy of natural reason” is what some scholars regard as unbiblical, and it is associated with other doctrinal problems.
In the first place, Aquinas assumed that human reason remains fully operative despite the Fall. Aquinas could hold that position in view of his separation of will and intellect (sin diverts will, not intellect, from its proper end), and of his distinction between the image and likeness of God in humanity. The “image” of God is human reason, without which men and women would not be human but merely animals. The “likeness” is moral, for human beings were created good. Sin therefore corrupts their moral likeness to God and perverts their will, but it does not destroy their essential identity as rational beings. Reformed theology, on the other hand, tends to regard the image and likeness as synonymous, so that sin affects both, depravity extends to all a person is, and reason is no longer religiously neutral—nor was it ever so.
In the second place, Aquinas’s confidence in philosophy rested on his adoption of Aristotelian realism, the view that the order observable in nature is due to universal and objectively real forms that determine an unchanging nature of things. That being so, the nature of things is equally accessible to all rational minds, rather than just to those enlightened by God’s grace. Understandably, the Lutheran thinker who follows Ockham and Luther in rejecting the realistic theory of universals is likely to lack Aquinas’s confidence that natural reason can gain universal truth.
On “Natural Theology” Aquinas’s position remains controversial, but his work is of such lasting significance that it still receives attention from many who are not Thomists. He is held in high regard as a philosopher both within and outside a Christian context. The reason is evident from a perusal of his prolific works. In addition to commentaries on Aristotle, commentaries on the Bible, theological and philosophical essays, and scripts of various public debates in which he engaged, he left two major works: the Summa Thelogica and Summa Contra Gentiles.
The Summa Theologica was prepared to instruct undergraduates in theology and is an encyclopedic statement of his teachings, meticulously developed and defended with replies to objections, real and hypothetical, of both Christian and non–Christian authorities. Written between 1265 and 1273, it provides a systematic compendium on all the theological, philosophical, and ethical topics debated in medieval universities, including what have become classical statements on such things as the relation of theology to philosophy, the arguments for God’s existence, the doctrine of creation, natural law, ethics, etc. Its organization reflects the Scholastic method: each question is divided into several sub–questions known as “articles.” Each article is introduced with objections to a standard position, following which Aquinas presents his own argument beginning “I answer that . . .” and then his replies to each initial objection. In the process he not only argues from Scripture but also considers the opinions of various Christian and non–Christian authorities—this in accordance with his view of the supplementary roles of reason and revelation. He divides theology into three major areas: God (including his relation to creation), Man (including his relation to God’s law and to grace), and Christ (including his person and work, his sacraments, and his church).
The Summa Contra Gentiles, equally exhaustive, is a reasoned account of the Christian faith addressed to the Islamic mind. Although an apologetic, it treated many of the same topics as the earlier treatise but with different purpose and emphasis. Both works had a profound effect on theology (Roman Catholic and otherwise) and on philosophy. They continue to attract scholarly attention.
Among Aquinas’s distinctive contributions are his natural theology and natural law ethic. Building on suggestions made by some of his predecessors, Aquinas formulated “five ways” of proving the existence of God. He rejected the famous ontological argument formulated by Anselm of Canterbury and did not regard the existence of God as self–evident to human beings, who do not initially know enough about God to know the necessity for his existence. His five ways, therefore, argued from universal truths about nature to nature’s cause and creator, God.
First, Aquinas observed that every natural process of change actualizes some potential. Firewood is potentially hot, but it becomes actually hot when it burns; yet it is not both potentially and actually hot at the same time. Nor can it both burn and be the cause of its own burning and of the changes that burning entails. The universal truth here is that whatever is changed or moved must be changed or moved by another. But an infinite chain of movers is impossible, for without a “first mover” there could be no first movement or change. Hence a first mover, itself moved by nothing else, must exist—namely an unchanging God.
Second, Aquinas observed in nature a seemingly endless array of cause–effect relations, “efficient causes” in his Aristotelian terminology. But that array is not actually endless, for nothing can be its own cause, as the whole causal order would be if it were actually endless. Therefore a first efficient cause of the whole array of causes must be admitted, namely God.
Third, nature exhibits a large variety of possibilities, things that are created and destroyed and therefore do not have to be. But if all that exists could possibly not exist, then at one point in an endless time past nothing at all could have existed, and consequently nothing would now exist. There must therefore exist some being whose existence is not merely possible but necessary by virtue of his very nature. That necessary being is God.
The first three “ways” argue from the dependent or contingent existence of finite things to the independent existence of God and are varieties of the so–called “cosmological argument.” Aquinas’s remaining two ways begin with order and purpose in nature and are variations of the “teleological argument,” as it was later called. The fourth way observes varying degrees of goodness, beauty, truth, and so forth in different things, each according to the form of its own species. This hierarchy of being and goodness implies that something must exist that is best, most beautiful, truest, most real. That something is in fact the God who is perfect in all his attributes.
The fifth and final way starts from the fact that even unthinking things follow natural and preestablished tendencies, as if they are deliberately pursuing some good end. But things do not pursue ends unless they are intelligent, or else are guided by an intelligent being. Therefore some intelligent being exists who draws all things to those ends, namely the God who works his purposes in and through the things he made.
The God whose existence these arguments purport to prove is a self–existent, all–powerful, all–good, intelligent creator. Human beings do not know from nature that he acts redemptively in history, but his “power and Godhead” are nonetheless attested by the creation (as Paul indicated in Rom. 1:20). “Natural theology,” as this kind of discussion is labeled, says less about God than does biblical theology, but it says enough to underscore all people’s responsibility to God and to prepare them for the fuller revelation in Scripture.
Aquinas’s natural theology also included arguments for human immortality, a topic much debated at that time because of the difficulty Aristotelians had in proving individual survival. Aquinas held that the human soul is actually a rational, intellectual being whose intellectual potential comes to be a reality in this life. Intellectual things are immaterial and so cannot be destroyed. Hence the soul, an intellectual thing, is indestructible and immortal. Another argument he offered depends on the idea that a final cause, or natural purpose, inheres in everything. In human beings it is revealed in a natural desire to live forever, not just through their descendants but as individuals. If this tendency inheres in human beings by nature, and nature does not lie, then they indeed are immortal. The first of these two arguments for human immortality was adapted from analogous attempts at such reasoning by Plato and Augustine. The second was more original with Aquinas. Both of the arguments are characteristic of the “proofs of immortality” employed in Christian apologetics ever since.
Running through Aquinas’s arguments for God’s existence and for immortality is the conviction that all nature has ends or “final causes” implanted by God. Evidence of those ends constitutes a natural revelation of God’s purposes for his creation. Aquinas accordingly developed a “natural law ethic” based on human knowledge of those ends, parallel to his natural theology.
With respect to “Ethics,” Aquinas distinguished (1) eternal law, (2) divine law, (3)natural law, and (4) human law. The eternal law is God’s unchanging wisdom and counsel, his eternal decree in accordance with which he created everything he made. The eternal law is revealed in two ways: divine law in the Scriptures entrusted to the church, and natural law, the nature of the creation itself. The theory of final causes means that the nature of every species of created things is such that it naturally tends to actualize its essential God–given possibilities, or in other words, it seeks its natural end or good. As rational beings, humans are so created as to seek a rationally ordered society, and they are created to know God. These are therefore ends they ought to pursue. But men and women are rational animals and share with other animals the natural ends of reproduction and the rearing of their young. They share with every “thing” the goal of self–preservation. The natural law then speaks of the preservation of life, including self–preservation; of sex and the family; of the social and political order and of religion. As natural theology affords less than biblical theology, so a natural law ethic affords less than biblical ethics. But the natural law enables human beings to identify universal and unchanging moral obligations which they face in all areas of life, obligations for which all are held accountable (as Paul pointed out in Romans 1 and 2). The fourth kind of law Aquinas discussed is human law, which is derived from natural law. Some human laws are universal because they are simply deduced from natural law—for example, laws against murder or theft. Others are more variable applications to specific situations, such as penal codes that assess ranges of punishment for particular crimes. But in both cases the natural law provides a moral yardstick for use in evaluating and formulating legislation. Aquinas accordingly talked about what makes a law unjust and what to do in that case. Questions of civil disobedience and conscientious objection are not new in our day; in fact, the contemporary debate draws heavily on Aquinas.
Natural law is universally the same, even though some human laws vary. So Aquinas provided a basis for international agreements about law. Some later Thomists developed that line of thought, asserting the need for a rule of law among the nations, a rule now called “international law.” They applied it to the legitimacy of going to war and to the conduct of war, developing in detail some of Aquinas’s tentative proposals. Aquinas had simply outlined a “just war theory,” bringing wars under the judgment of “just laws” rooted in natural law.
The influence of Thomas Aquinas even today is profound and widespread: it is seen in theology, philosophy, ethics, and in major issues facing government and other branches of society. A Christian of such deep, broad, and lasting impact is the kind of thinker with the kind of vision that the church needs in every age. A. F. Holmes

This Biographical Sketch comes from…

Who’s Who in Christian History

Who's Who in Christian HistoryAuthor: Douglas, J. D.; Comfort, Philip Wesley.; Mitchell, Donald
Publisher: Tyndale House |
Publication Date: 1997, c1992.

With over 1,500 biographical entries, this bibliographical dictionary is a comprehensive resource, spanning the first through the twentieth centuries-from Jesus and the apostles to Billy Graham and Mother Teresa. Any reader will be fascinated and inspired by the lives of men and women-well known and obscure-who were influential in Christian history. This one volume biographical dictionary is also a perfect resource for pastors, Bible teachers, Sunday school teachers, Bible students, and seminarians.

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