Chap. 3: An Overview of the Thought of Aquinas
CHAP. 3: AN OVERVIEW OF THE THOUGHT OF AQUINAS
THE THOUGHT OF AQUINAS IS RICH AND VARIED. He wrote on many topics, including faith and reason, revelation, knowledge, reality, God, analogy, creation, human beings, government, and ethics. His mind was intensely analytic, making his arguments difficult for the modern reader to follow. Furthermore, his style is syllogistic and highly complex. So that the reader does not get lost in the intricacies of Aquinas's views, it will be helpful to present an introductory summary of many of his basic ideas, especially those of interest to evangelicals. The rest of the book will then treat these major topics in more depth.
Revelation
God has revealed himself in both nature and Scripture. His natural revelation (Rom. 1:19-20) is available to all people and is the basis for natural theology. The creation reveals one God and his essential attributes, but not the Trinity or the unique doctrines of the Christian faith, such as the incarnation of Christ or the way of salvation. This revelation in nature also includes a moral law that is binding on all people (Rom. 2:12-15).
God's divine law is for believers; it is revealed in Scripture. Although written by humans utilizing different literary styles,1 the Bible is the only divinely authoritative writing.2 The Bible is inspired and inerrant, even in matters that are not essential to our redemption.3 No other Christian writing, neither the fathers nor the creeds, are inspired or revelatory. They are only human interpretations of God's revelation in Scripture.4
Faith and Reason
Following Augustine, Aquinas believes faith is based on God's revelation in Scripture. Support for faith, however, is found in miracles and probable arguments.5 Although God's existence is provable by reason, sin obscures our ability to know6 and so belief (not proof) that God exists is necessary for most persons?7 Human reason, however, is never the basis for faith in God. Demanding reasons for belief in God actually lessens the merit of faith.8 Believers, nonetheless, should reason about and for their faith.
According to Aquinas, there are five ways we can use reason to demonstrate God's existence. We can argue: (1) from motion to an Unmoved Mover; (2) from effects to a First Cause; (3) from contingent being to a Necessary Being; (4) from degrees of perfection to a Most Perfect Being; and (5) from design in nature to a Designer of nature.9 Behind these arguments is the premise that all finite, changing beings need a cause outside themselves.
However, there are mysteries of the Christian faith, such as the Trinity and the incarnation, which cannot be known by human reason but only by faith in God's revelation in Scripture.10 These mysteries go beyond reason, but are not contrary to reason.
Knowledge
Aquinas believes that knowledge comes either by supernatural revelation (in Scripture) or by natural means. All natural knowledge begins in experience.11 We are born, however, with an a priori, natural, innate capacity to know.12 Everything that is in our mind was first in the senses, except the mind itself.
Knowing something for certain is possible by means of first principles. First principles are known by way of inclination before they are known by cognition. These include: (1) the principle of identity (being is being); (2) the principle of non-contradiction (being is not non-being); (3) the principle of excluded middle (either being or nonbeing); (4) the principle of causality (nonbeing cannot cause being); and (5) the principle of finality (every being acts for an end). By these first principles the mind can attain knowledge of reality—even some certain knowledge. Once the terms are properly understood, these first principles are self-evident, that is, they are undeniable.13
Reality
Like Aristotle, Aquinas believes it is the function of the wise person to know order. The order reason produces in its own ideas is called logic. The order reason produces through acts of the will is known as ethics. The order reason produces in external things is art. The order reason contemplates (but does not produce) is nature. Nature contemplated insofar as it is sensible is physical science. Nature studied insofar as it is quantifiable is mathematics.14 Nature or reality studied insofar as it is real is metaphysics. Metaphysics, then, is the study of the real as real or being insofar as it is being.
The heart of Aquinas's metaphysics is the real distinction between essence (what something is) and existence (that which is) in all finite beings.15 Aristotle had distinguished between actuality and potentiality, but applied this only to things composed of form and matter, not to the order of being as such. Aquinas takes Aristotle's distinction between act and potency and applies it to form (being).
Aquinas argues that only God is Pure Being, Pure Actuality, with no passive potentiality whatsoever. God, of course has “active potency” or power. In fact, he is all-powerful. But the central premise of the Thomistic view of reality is that act in the order in which it is act is unlimited and unique, unless it is cojoined with passive potency. God alone is Pure Act (or Actuality) with no potentiality or form. Angels are completely actualized potentialities (pure Forms). Humankind is a composition of form (soul) and matter (body) which is progressively actualized.
God
God alone is Being (I am-ness) pure and simple. Everything else merely has being. God's essence is identical to his existence. It is of his essence to exist. That is, God is a Necessary Being. He cannot not exist. Neither can God change, since he has no potentiality to be anything other than what he is. Likewise, God is eternal, since time implies a change from a before to an after. But as the "I Am," God has no befores and afters. God also is simple (indivisible) since he has no potential for division. And he is infinite, since Pure Act as such is unlimited, having no potentiality to limit it.16 Besides these metaphysical attributes, God is also morally perfect and infinitely wise.17
Analogy
Natural knowledge of God is derived from his creation the way an efficient cause is known from its effects. Since God made the world, his creation resembles him. It is not the same as him (univocal), but it is like him. Our natural knowledge of God is based on that resemblance or analogy. Neither can it be totally different from him (equivocal), since the cause communicates something of itself to its effects.
Univocal (totally the same) knowledge of God is impossible, since our knowledge is limited and God is unlimited. Equivocal (totally different) knowledge of God is impossible, since creation resembles the Creator; the effect resembles its efficient cause. Of course, there are great differences between God and creatures. Hence, the via negativa (the way of negation) is necessary. That is, we must negate all limitations from our concepts before we apply them to God. We must apply to God only the perfection signified (goodness, truth, etc.), but not the finite mode of signification. So the same attribute will have the same definition for creatures and Creator but a different application or extension. The reason for this is that creatures are only finitely good while God is infinitely Good. So before we can appropriately apply the term "good" to God, we must negate the finite mode (how) in which we find good among creatures and apply the meaning (what) to God in an unlimited way.18
Creation
God did not create the world out of himself (ex Deo) or out of preexisting matter (ex materia). Rather, he created it out of nothing (ex nihilo).
Although an eternal creation is theoretically possible (since there is no logical reason an eternal cause cannot be causing eternally), nevertheless, divine revelation teaches that the universe had a beginning. So God created a temporal universe. There was literally no time before God created—only eternity. God did not create in time; rather, with the world there was the creation of time. So there was no time before time began.19
Further, the universe is dependent on God for its existence. He not only caused it to come to be, but he also causes it to continue to be. God is both the Cause of the origination of the whole of creation and the Cause of its continuation. The universe is absolutely dependent on God; it is contingent. Only God is necessary.
Human Beings
A human being is a matter/form unity of soul and body. Despite this unity, there is no identity between soul and body. The soul survives death and awaits reunion with the physical body at the final resurrection.20 The human soul is the formal cause while the body is the material cause of a human being. God, of course, is the efficient cause. Parents are only the instrumental cause of the body. The final cause (purpose) is to glorify God, who created us. Adam was directly created by God at the beginning, and God directly creates each new soul in the womb of its mother.21
Ethics
Just as there are first principles of thought, so there are first principles of action, called laws. Aquinas distinguishes four kinds of law. Eternal law is the plan by which God governs creation. Natural law is the participation of rational creatures in this eternal law. Human law is a particular application of natural law to local communities. Divine law is the revelation of God's law through Scripture to believers.22
Aquinas divides virtues into two classes: natural and supernatural. The former include prudence, justice, courage, and temperance. These are revealed through natural revelation and are applicable to all human beings. Supernatural virtues consist of faith, hope, and love. They are known from supernatural revelation in Scripture and are binding on believers.23
Works on Aquinas
There are many helpful tools for studying Aquinas. Some of the more important reference works include the following:
Bonin, Therese. Bibliography of full listing of all English translations of Aquinas at Duequesne University at www.home.duq.edu/-bonin/thomasbibliogrpahy.html
Bourke. Thomistic Bibliography. Greenwood, 1980.
Busa, Roberto, ed. Opera Omina [CD-ROM in Latin]. Stuttgart: Frommann-Holzboog, 1996.
Busa, Roberto. Index Thomisticus. This is a concordance of the writings of Aquinas, published by the Jesuite scholasticate in Gallarate, North Italy, 1979.
Deferrari, R. J. A Complete Index of the Summa Theologiae of St. Thomas Aquinas. Catholic University of America Press, 1956.
Latin-English Dictionary of Thomas Aquinas. Daughters of St.Paul, 1960.
A Lexicon of St. Thomas Aquinas Based on Summa Theologiae and Select Passages of His Other Work. Catholic University of America Press, 1960.
Mandonnet, P., and J. Destrez. Bibliographic Thomiste. Paris, 1921. Miethe, Terry, and Vernon
McDermott, Timothy, trans. Select Writings [of Aquinas]. Oxford University Press, 1993.
McKeon, Richard, ed. Selections from Medieval Philosophers. Vol. 2. Contains a Latin dictionary of key terms.
Schutz, Ludwig. Thomas-Lexicon [in German and Latin] Paderborn: Schoningh, 1895
Stockhammer, Morris. Thomas Aquinas Dictionary. Philosophical Library, 1965.
Repertoire bibliographique, published under various titles by Louvain, 1895-1963.
CD-ROM: Past Masters: Humanities Databases, Full Text, Scholarly Editions (Charlottesville, VA; InteLex, 1992) with all of Aquinas’s translated works.
Journals that Feature or Contain Articles on Aquinas
The Aquinas Papers, Blackfriars, London.
Modern Schoolman, St. Louis University.
New Scholasticism, American Catholic Philosophical Association.
Proceedings of Jesuit Society (fewer articles on Aquinas since Vatican II).
Speculum (a journal of medieval studies).
The Review of Metaphysics (The Catholic University of America)
Thomist (published by the Dominican Fathers).