The "Go-Between" of Past and Future
Since "centrality" is also a part of the definition of pivotal, it is helpful to note that Aquinas is also pivotal chronologically. That is so because he stands roughly in the center, or the middle, of the development of the church's doctrine and dogma from its inception some eight centuries before him, and its continuation roughly eight centuries after him. Thus he systematized and updated for his time (the "High Middle Ages," or the years 1100's-1300's) the teachings of the best early Catholic philosophers and theologians. These are the four traditional Doctors of the Latin Church: St. Ambrose (339-97); St. Jerome (342-420); St. Augustine (354-430 A.D.) and St. Pope Gregory the Great (505-604, who was pope from 590). Further, St. Thomas developed the tone, the terminology, the categories and conclusory theses that were used by the best philosophers after his time, from the Renaissance (1300's - 1600's) onward.
By serving as the synthesizer of the "before" of Catholic doctrine and dogma, and the progenitor of the "after," Thomas became in effect the founding father of all Catholic philosophy and theology.
Scholasticism and the "Summae"
Saint Thomas Aquinas, O.P. (1225–1274), was an Italian Dominican priest and the leading philosopher and theologian in the tradition of Scholasticism. ("Scholasticism" may be defined as a method of philosophical and theological speculation which aims at a better understanding of revealed truths.) Scholastic philosophers and theologians put their theses into the form of "Summae," or summary-condensed versions of the subject-matter which they taught. ("Summae" is the plural of "Summa," the latter of which refers to just one such summary). Aquinas excelled at presenting his theories in the form of Summae. His Summa Theologica.
His most famous Summa was the "Summa Theologica ("Summation of Theology")," which is a vast structure of treatises, questions and articles which fall into three parts: The first part treats of God considered in Himself and as the principle of creation. The second part treats of God as the end of man, and of man's return to God. The third part treats of Christ as the way of man to God. Within the Scholastic trend of nick-naming its leading thinkers, Aquinas became known as the "Angelic Doctor," for the brilliance of his Summae.
"Thomism," and "Natural Theology"
He was the foremost classical proponent of natural theology, and the father of an entirely new school of Catholic theology and philosophy, known as Thomism. Thomism was philosophy-theology patterned after "Thomas," which flourished well into the 20th Century. Philosophers who base their work on St. Thomas in modern times are called "Neo (or "New")-Thomists." St. Thomas' influence on Catholic thought is fundamental and primary. Further, much of modern secular philosophy was conceived in the development or refutation of his ideas, particularly in the areas of ethics, natural law, metaphysics (the science of existence), and political theory.
Thomas' great work on "natural theology" was the body of knowledge about God which may be obtained by human reason alone without the aid of revelation, and hence contrasted with "revealed theology." St. Paul had been the first to write about this distinction between natural and revealed theology in his Epistle to the Romans, where he writes, "[W]hat can be known about God is evident to [those philosophers who question what is known about God], because God made it evident to them. Ever since the creation of the world, His invisible attributes of eternal power and divinity have been able to be understood and perceived in what He has made." (Romans 1:19-20).
St. Thomas wholeheartedly supported St. Paul's statement, and philosophically expanded St. Paul's teaching in Romans. In fact one can summarize the overall achievement of St. Thomas by saying that he developed his philosophy so that it upheld and supported divine revelation, making of revelation something that could be expressed in philosophical language. In doing this, Thomas established philosophy as a scientific exposition of Catholic theology, making it relevant to the academic and intellectual thinking of his time, while nonetheless keeping his philosophy in line with the Church's teaching on divine revelation. If one were to ask where St. Thomas's writings stood on the Scripture versus Tradition continuum, one could best say that Thomas' philosophical-theological writing incorporated Scripture into a new form of Tradition. In the Thomist Tradition, the greatest classical Greek philosophers were represented as supportive of Scripture.
The Church's Model Teacher
Thomas was long held in the Catholic Church to be the model teacher for those studying for the priesthood, and his thought as the highest expression of both natural reason and speculative theology. The study of his works, according to papal and magisterial documents, was long a core of the required program of study for those seeking ordination as priests or deacons, as well as for those in religious formation and for other students of the sacred disciplines (Catholic philosophy, theology, history, liturgy, and canon law). One of the 35 Doctors of the Church, he is considered the Church's greatest theologian and philosopher. Pope Benedict XV declared: "This (Dominican) Order ... acquired new luster when the Church declared the teaching of Thomas to be her own and that Doctor, honored with the special praises of the Pontiffs, the master and patron of Catholic schools."
His Philosophy Based on Revelation
Although Thomas was a theologian and the leading Scholastic philosopher, he never considered himself a philosopher, and criticized philosophers, whom he saw as pagans, for always "falling short of the true and proper wisdom to be found in Christian revelation." With this in mind, however, Thomas greatly respected Aristotle (384-322 B.C.), so much so that in his Summa, he often cites Aristotle simply as "the Philosopher." Despite his emphasizing divine revelation in what he wrote, his work updates philosophical topics, and in this sense may be characterized as philosophical. Thomas's philosophical thought has exerted enormous influence on subsequent Christian theology, especially that of the Catholic Church, and extending to Western secular philosophy in general.
Plato, Aristotle and Church Teaching
Prior to Thomas, Platonism, or the philosophy of Plato (428-347 B.C.), was considered by Christian thinkers as the only philosophy sufficient to serve as the basis of Christian theology. In other words, before Thomas, Plato was the Philosopher. However, shortly before Thomas began to study philosophy, European contact with the Arabic east led to the western discovery of what had been in the European Church otherwise lost portions of Aristotle. St. Thomas' philosophy received its characteristic shape under the influence of the Church's newly discovered metaphysical writings of Aristotle.
Though a student of Plato, Aristotle's philosophical position was very different than Plato's. Plato thought that all individual things in creation were based in their "Ideas." Thus, for example, Plato thought that a tree possessed reality only in the Idea of "Treeness." Plato conceived the Ideas as arranged in a hierarchy, at the head of which was the "Idea of the Good." Plato's "Good" alone had reality for him, and came close to being, but not quite arriving at, the Idea of God. Aristotle asserted that an Idea exists only as expressed in an individual object. Thus he maintained against Plato, that, so far from there being an Idea called "treeness," for example, possessing existence in its own right, it was the union of the "form" tree with "matter" which makes the real individual tree.
It is easy to see why Plato, with his supreme Idea of the Good, was the favorite philosopher of the Catholic Church when St. Thomas arrived on the scene. Aristotle's philosophy was regarded with suspicion, largely because his teachings were thought to lead to a materialistic view of the world. But St. Thomas built up his system on an avowedly Aristotelian basis, following Aristotle's incarnational, scientific lead. Thomas' upholding of Aristotle over Plato persuaded Latin philosophical theologians in the West during Thomas' time to make Aristotle the founder of a new Christian philosophy, namely the new Thomist philosophy. Thomas essentially dethroned Plato as the philosopher within Christianinty, and replaced him with Aristotle. Thomas wrote several important commentaries on Aristotle's works, including On the Soul,Ethics and Metaphysics, which placed him at odds with many traditionalist Catholic thinkers.
Thomas believed that to find the knowledge of any truth whatsoever man needs divine help, but that the intellect may be moved by God to its act. Following Aristotle, he believed that human beings have the natural capacity to know many things without special divine revelation, even though such revelation occurs from time to time, as Thomas put it, "especially in regard to such (truths) as pertain to faith." But faith is the light that is given to man by God according to man's nature: In his typically turgid philosophical jargon, Thomas wrote, "Every form bestowed on created things by God has power for a determined actuality. And thus the human understanding has a form, viz. intelligible light, which of itself is sufficient for knowing certain intelligible things, viz. those we can come to know through the senses."
In his Summa theologiae, Thomas wrote: "Virtue denotes a certain perfection of a power. Now a thing's perfection is considered chiefly in regard to its end. But the end of power is act. Wherefore power is said to be perfect, according as it is determinate to its act."
Thomas especially followed Aristotle on the latter's distinction between "potential" and "act." As an acorn exists in potential to the oak tree, when it acts, growing into the tree, it has achieved the purpose of its existence. Plato taught that existence is in the eternal, pre-existing Idea of something, and thus created things evolved from their Idea, or their pre-existing basis.
Thomas defined the four cardinal virtues as prudence, temperance, justice, and fortitude. The cardinal virtues are natural and revealed in nature, and they are binding on everyone. There are, however, three theological virtues: faith, hope, and charity. These are somewhat supernatural and are distinct from the cardinal virtues in their object, namely, God: "Now the object of the theological virtues is God Himself, Who is the last end of all, as surpassing the knowledge of our reason. On the other hand, the object of the cardinal, or intellectual and moral virtues, is something comprehensible to human reason. Wherefore the theological virtues are specifically distinct from the cardinal virtues."
Furthermore, Thomas distinguished four kinds of law: eternal, natural, human, and divine. Eternal law is the decree of God that governs all creation. Natural law is the human "participation" in the eternal law and is discovered by reason. Natural law, of course, is based on "first principles." [T]his is the first precept of the law, that good is to be done and promoted, and evil is to be avoided. All other precepts of the natural law are based on this.
The desires to live and to procreate are counted by Thomas among those basic (natural) human values on which all human values are based. According to Thomas, all human tendencies -- in their potential -- are geared in act towards real human goods. In this case, the human nature in question is marriage, the total gift of oneself to another that ensures a family for children and a future for mankind. To clarify for Christian believers, Thomas defined love as "to will the good of another." Human law is positive law: the natural law applied by governments to societies. Divine law is the specially revealed law in the Scriptures.
Thomas viewed theology, or the sacred doctrine, as a science, the raw material data of which consists of written scripture and the tradition of the Catholic Church. These sources of data were produced by the self-revelation of God to individuals and groups of people throughout history. Faith and reason, while distinct but related, are the two primary tools for processing the data of theology. Thomas believed both faith and reason were necessary for one to obtain true knowledge of God. He blended Aristotle's philosophy and Christian doctrine by suggesting that rational thinking and the study of nature, like revelation, were valid ways to understand truths pertaining to God. According to Thomas, God reveals himself through nature, so to study nature is to study God. The ultimate goals of theology, in Thomas's mind, are to use reason to grasp the truth about God and to experience salvation through that truth. Reason and Faith.
Thomas thus believed that truth is known through reason (natural revelation) and faith (supernatural revelation). Supernatural revelation has its origin in the inspiration of the Holy Spirit and is made available through the teaching of the prophets, summed up in Holy Scripture, and transmitted by the Magisterium, the sum of which is called "Truth." Natural revelation is the truth available to all people through their human nature; certain truths all men can attain from correct human reasoning. For example, he felt this applied to rational ways to know the existence of God.
Though one may deduce the existence of God and his Attributes (One, Truth, Good, Power, Knowledge) through reason, certain specifics may be known only through special revelation (such as the Trinity). In Thomas's view, special revelation is equivalent to the revelation of God in Jesus Christ. The major theological components of Christianity, such as the Trinity and the Incarnation, are revealed in the teachings of the Church and the Scriptures and may not otherwise be deduced. However, supernatural revelation (faith) and natural revelation (reason) are complementary rather than contradictory in nature, for they pertain to the same unity: truth.
On Just War
St. Augustine (see page 1) had believed that Christians should be pacifists, but that they should use defense as a means of preserving peace in the long run. For example he argued that Pacifism did not apply to the defense of innocents. In essence, the pursuit of peace must include the option of fighting to preserve it in the long-term. Such a war could not be preemptive, but had to be defensive, to restore peace. St. Thomas used the authority of Augustine's arguments in an attempt to define the conditions under which a war could be just. He laid these out in his historic work, Summa Theologica:
First, war must occur for a good and just purpose rather than for self-gain or as an exercise of power. Second, just war must be waged by a properly instituted authority such as the state. Third, peace must be a central motive even in the midst of violence.
Proving God's Existence
Thomas believed that the existence of God can be proven. In the Summa theologiae, he considered in great detail five reasons for the existence of God. These are widely known as the quinque viae, or the "Five Ways."
The Five Ways Aquinas Tried to Prove God's Existence: Thomas' five proofs for the existence of God take some of Aristotle's assertions concerning principles of being. For Thomas, God as prima causa (first cause) comes from Aristotle's concept of the unmoved mover and asserts that God is the ultimate cause of all things.
Motion: Some things are undoubtedly undergoing motion, though cannot cause their own motion. Since Thomas believed there can be no infinite chain of causes of motion, this leads to the conclusion there must be a first cause of motion that is not itself moved by anything else, and this is what everyone understands by God.
Causation: Like motion, nothing can cause itself, and like motion there must be a First Cause, called God
Existence of necessary and the unnecessary: Our experience includes things certainly existing but apparently unnecessary. Therefore, we are compelled to suppose something that exists necessarily, having this necessity only from itself; in fact itself the cause why other things exist.
Gradation: If we can notice a gradation in things in the sense that some things are more hot, good, etc., there must be a superlative which is the truest and noblest thing, and so most fully existing. This then, we call God.
Ordered tendencies of nature: A direction of actions to an end is noticed in all bodies following natural laws. Anything without awareness tends to a goal under the guidance of one who is aware. This we call God.
The Nature of God
Thomas felt the best approach, commonly called the via negativa, is to consider what God is not. This led him to propose five statements about the divine qualities:
(1) God is simple, without composition of parts, such as body and soul, or matter and form.
(2) God is perfect, lacking nothing. That is, God is distinguished from other beings on account of God's complete actuality, whereas everything created exists in potential, moving toward actuality. Thomas defined God as the "subsisting act of being."
(3) God is infinite, i.e., God is not finite in the ways that created beings are, physically, intellectually, and emotionally limited. This infinity is to be distinguished from infinity of size and infinity of number.
(4) God is immutable, i.e., incapable of change on the levels of God's essence and character.
(5) God is one, i.e., without diversification within God's self. The unity of God is such that God's essence is the same as God's existence. In Thomas's words, "in itself the proposition 'God exists' is necessarily true, for in it subject (God) and predicate (existence) are the same."
Nature of the Trinity
Thomas argued that God, while perfectly united, also is perfectly described by Three Interrelated Persons. These three persons (Father, Son, and Holy Spirit) are constituted by their relations within the essence of God. The Father generates the Son (or the Word) by the relation of self-awareness. This eternal generation then produces an eternal Spirit "who enjoys the divine nature as the Love of God, the Love of the Father for the Word."
This Trinity exists independently from the world. It transcends the created world, but the Trinity also decided to give grace to human beings. This takes place through the Incarnation of the Word in the person of Jesus Christ and through the indwelling of the Holy Spirit within those who have experienced salvation by God.
Nature of Jesus Christ
In his Summa Theologica, Thomas begins his discussion of Jesus Christ by recounting the biblical story of Adam and Eve and by describing the negative effects of original sin. The purpose of Christ's Incarnation was to restore human nature by removing "the contamination of sin", which humans cannot do by themselves. "Divine Wisdom judged it fitting that God should become man, so that thus one and the same person would be able both to restore man and to offer satisfaction." Thomas argued in favor of the satisfaction view of atonement; that is, that Jesus Christ died "to satisfy for the whole human race, which was sentenced to die on account of sin."
Thomas argued against several specific contemporary and historical theologians who held differing views about Christ. Thomas stated that Jesus was truly divine and not simply a human being. He argued that the fullness of God was an integral part of Christ's existence. However, Thomas held that Christ had a truly human (rational) soul, as well. This produced a duality of natures in Christ. In short, "Christ had a real body of the same nature of ours, a true rational soul, and, together with these, perfect Deity." Thus, there is both unity (in his one personhood) and composition (in his two natures, human and Divine) in Christ.
Echoing St. Bishop Athanasius of Alexandria (296-373), Thomas said that "The only begotten Son of God...assumed our nature, so that he, made man, might make men gods."
Treatment of Heretics
Thomas Aquinas belonged to the Dominican Order (formally Ordo Praedicatorum, the Order of Preachers) which began as an order dedicated to the conversion of the Albigensians and other heterodox factions, at first by peaceful means; later the Albigensians were dealt with by means of the Albigensian Crusade. In the Summa theologiae, Thomas wrote:
"With regard to heretics two points must be observed: one, on their own side; the other, on the side of the Church. On their own side there is the sin, whereby they deserve not only to be separated from the Church by excommunication, but also to be severed from the world by death. On the part of the Church, however, there is mercy which looks to the conversion of the wanderer, wherefore she condemns not at once, but 'after the first and second admonition,' as the Apostle directs: after that, if he is yet stubborn, the Church no longer hoping for his conversion, looks to the salvation of others, by excommunicating him and separating him from the Church, and furthermore delivers him to the secular tribunal to be exterminated thereby from the world by death."
Goal of human life
In Thomas's thought, the goal of human existence is union and eternal fellowship with God. Specifically, this goal is achieved through the beatific vision, an event in which a person experiences perfect, unending happiness by seeing the very essence of God. This vision, which occurs after death, is a gift from God given to those who have experienced salvation and redemption through Christ while living on earth.
This ultimate goal carries implications for one's present life on earth. Thomas stated that an individual's will must be ordered toward right things, such as charity, peace, and holiness. He sees this as the way to happiness. Thomas orders his treatment of the moral life around the idea of happiness. The relationship between will and goal is antecedent in nature "because rectitude of the will consists in being duly ordered to the last end [that is, the beatific vision]." Those who truly seek to understand and see God will necessarily love what God loves. Such love requires morality and bears fruit in everyday human choices.
Thomas, following Church doctrine, accepts that the soul continues to exist after the death of the body. Because he accepts that the soul is the form of the body, then he also must believe that the human being, like all material things, is a form-matter composite, which is Aristotle's principle philosophy of creation. Substantial form (the human soul) configures prime matter (the physical body) and is the form by which a material composite belongs to that species it does; in the case of human beings, that species is rational animal.
Aquinas says that the soul shares in the material and spiritual worlds, and so has some features of matter and other, immaterial, features (such as access to universals). The human soul is different from other material and spiritual things; it is created by God, but also only comes into existence in the material body.
Human beings are material, but the human person can survive the death of the body through continued existence of the soul, which persists. The human soul straddles the spiritual and material worlds, and is both a configured subsistent form as well as a configurer of matter into that of a living, bodily human. Because it is spiritual, the human soul does not depend on matter and may exist separately. Because the human being is a soul-matter composite, the body has a part in what it is to be human. Perfected human nature consists in the human dual nature, embodied and intellecting.
Aquinas believes the soul persists after the death and corruption of the body, and is capable of existence, separated from the body between the time of death and the resurrection. Aquinas knows that human beings are essentially physical, but that that physicality has a spirit capable of returning to God after life. For Aquinas, the rewards and punishment of the afterlife are not only spiritual. Because of this, resurrection is an important part of his philosophy on the soul. The human is fulfilled and complete in the body, so the hereafter must take place with souls "enmattered" in resurrected bodies. In addition to spiritual reward, humans can expect to enjoy material and physical blessings. Because Aquinas’s soul requires a body for its actions, during the afterlife the soul will also be punished or rewarded in corporeal existence.