At Paris he had Albert the Great as one of his teachers (1245). When Albert was transferred to Cologne Thomas followed him, and continued to study with him there till 1252. At times Thomas seemed dull, but Albert defended him, and prophesied his greatness.55 He returned to Paris to teach as a bachelor in theology; and now, following in his master’s steps, he began a long series of works presenting Aristotle’s philosophy in Christian dress. In 1259 he left Paris to teach at the studium maintained by the papal court now in Anagni, now in Orvieto, now in Viterbo. At the papal court he met William of Moerbeke, and asked him to make Latin translations of Aristotle directly from the Greek.
Meanwhile Siger of Brabant was leading an Averroistic revolution at the University of Paris. Thomas was sent up to meet this challenge. Reaching Paris, he brought the war into the enemy’s camp with a tract On the Unity of the Intellect Against the Averroists (1270). He concluded it with unusual fire:
Behold our refutation of these errors. It is based not on documents of faith but on the reasons and statements of the philosophers themselves. If, then, there be anyone who, boastfully taking pride in his supposed wisdom, wishes to challenge what we have written, let him not do it in some corner, nor before children who are powerless to decide on such difficult matters. Let him reply openly if he dare. He shall find me here confronting him, and not only my negligible self, but many another whose study is truth. We shall do battle with his errors, and bring a cure to his ignorance.56
It was a complex issue, for Thomas, in this his second period of teaching at Paris, had not only to combat Averroism, but also to meet the attacks of fellow monks who distrusted reason, and who rejected Thomas’ claim that Aristotle could be harmonized with Christianity. John Peckham, successor to Bonaventura in the Franciscan chair of philosophy at Paris, upbraided Thomas for sullying Christian theology with the philosophy of a pagan. Thomas—Peckham later reported—stood his ground, but answered “with great mildness and humility.”57 Perhaps it was those three years of controversy that undermined his vitality.
In 1272 he was called back to Italy at the request of Charles of Anjou to reorganize the University of Naples. In his final years he ceased writing, whether through weariness or through disillusionment with dialectics and argument. When a friend urged him to complete his Summa theologica he said: “I cannot; such things have been revealed to me that what I have written seems but straw.”58 In 1274 Gregory X summoned him to attend the Council of Lyons. He set out on the long mule ride through Italy; but on the way between Naples and Rome he grew weak, and took to his bed in the Cistercian monastery of Fossanuova in the Campagna. There, in 1274, still but forty-nine, he died.
When he was canonized witnesses testified that he “was soft-spoken, easy in conversation, cheerful and bland of countenance… generous in conduct, most patient, most prudent; radiant with charity and gentle piety; wondrous compassionate to the poor.”59 He was so completely captured by piety and study that these filled every thought and moment of his waking day. He attended all the hours of prayer, said one Mass or heard two each morning, read and wrote, preached and taught, and prayed. Before a sermon or a lecture, before sitting down to study or compose, he prayed; and his fellow monks thought that “he owed his knowledge less to the effort of the mind than to the virtue of his prayer.”60 On the margin of his manuscripts we find, every now and then, pious invocations like Ave Maria!61 He became so absorbed in the religious and intellectual life that he hardly noticed what happened about him. In the refectory his plate could be removed and replaced without his being aware of it; but apparently his appetite was excellent. Invited to join other clergymen at dinner with Louis IX, he lost himself in meditation during the meal; suddenly he struck the table with his fist and exclaimed: “That is the decisive argument against the Manicheans!” His prior reproved him: “You are sitting at the table of the King of France”; but Louis, with royal courtesy, bade an attendant bring writing materials to the victorious monk.62 Nevertheless the absorbed saint could write with good sense on many matters of practical life. People remarked how he could adjust his sermons either to the studious minds of his fellow monks, or to the simple intellects of common folk. He had no airs, made no demands upon life, sought no honors, refused promotion to ecclesiastical office. His writings span the universe, but contain not one immodest word. He faces in them every argument against his faith, and answers with courtesy and calm.
Improving upon the custom of his time, he made explicit acknowledgments of his intellectual borrowings. He quotes Avicenna, al-Ghazali, Averroës, Isaac Israeli, Ibn Gabirol, and Maimonides; obviously no student can understand the Scholastic philosophy of the thirteenth century without considering its Moslem and Jewish antecedents. Thomas does not share William of Auvergne’s affection for “Avicebron,” but he has a high respect for “Rabbi Moyses,” as he calls Moses ben Maimon. He follows Maimonides in holding that reason and religion can be harmonized, but also in placing certain mysteries of the faith beyond the grasp of reason; and he cites the argument for this exclusion as given in the Guide to the Perplexed.63 He agrees with Maimonides that the human intellect can prove God’s existence, but can never rise to a knowledge of His attributes; and he follows Maimonides closely in discussing the eternity of the universe.64* In logic and metaphysics he takes Aristotle as his guide, and quotes him on almost every page; but he does not hesitate to differ from him wherever the Philosopher strays from Christian doctrine. Having admitted that the Trinity, the Incarnation, the Redemption, and the Last Judgment cannot be proved by reason, he proceeds on all other points to accept reason with a fullness and readiness that shocked the followers of Augustine. He was a mystic in so far as he acknowledged the suprarationality of certain Christian dogmas, and shared the mystic longing for union with God; but he was an “intellectualist” in the sense that he preferred the intellect to the “heart” as an organ for arriving at truth. He saw that Europe was bound for an Age of Reason, and he thought that a Christian philosopher should meet the new mood on its own ground. He prefaced his reasonings with Scriptural and Patristic authorities, but he said, with pithy candor: Locus ab auctoritate est infirmissimus—“the argument from authority is the weakest.”66 “The study of philosophy,” he wrote, “does not aim merely to find out what others have thought, but what the truth of the matter is.”67 His writings rival those of Aristotle in the sustained effort of their logic.
Seldom in history has one mind reduced so large an area of thought to order and clarity. We shall find no fascination in Thomas’ style; it is simple and direct, concise and precise, with not a word of padding or flourish; but we miss in it the vigor, imagination, passion, and poetry of Augustine. Thomas thought it out of place to be brilliant in philosophy. When he wished he could equal the poets at their own game. The most perfect works of his pen are the hymns and prayers that he composed for the Feast of Corpus Christi. Among them is the stately sequence Lauda Sion salvatorem, which preaches the Real Presence in sonorous verse. In the Lauds is a hymn beginning with a line from Ambrose—Verbum supernum prodiens—and ending with two stanzas—O salutaris hostia—regularly sung at the Benediction of the Sacrament. And in the Vespers is one of the great hymns of all time, a moving mixture of theology and poetry:
Pange, lingua, gloriosi
corporis mysterium
sanguinisque pretiosi,
quem in mundi pretium
fructus ventris generosi,
rex effudit gentium.
Nobis datus, nobis nacus
ex intacta virgine,
et in mundo conversatus,
sparso verbi semine,
sui moras incolatus
miro clausit ordine.
In supremae nocte cenae
recumbens cum fratribus,
observata lege plene
cibis in legalibus,
cibum turbae duodenae
se dat suis manibus.
Verbum caro panem verum
verbo carnem efficit,
fitque s
anguis Christi merum,
et, si sensus deficit,
ad firmandum cor sincerum
sola fides sufficit.
Tantum ergo sacramentum
veneremur-cernui,
et antiquum documentum
novo cedat ritui;
praestet fides supplementum
sensuum defectui.
Genitori genitoque
laus et iubilatio
salus, honor, virtus quoque
sit et benedictio;
procedenti ab utroque
compar sit laudatio.*
Sing, O tongue, the mystery
of the body glorious,
and of blood beyond all price,
which, in ransom of the world,
fruit of womb most bountiful,
all the peoples’ King poured forth.
Given to us and born for us
from an untouched maid,
and, sojourning on the planet,
spreading seed of Word made flesh,
as a dweller with us lowly,
wondrously He closed His stay.
In the night of the Last Supper,
with apostles while reclining,
all the ancient law observing
in the food by law prescribed,
food He gives to twelve assembled,
gives Himself with His own hands.
Word made flesh converts true bread
with a word into His flesh;
wine becomes the blood of Christ,
and if sense should fail to see,
let the pure in heart be strengthened
by an act of faith alone.
Therefore such great sacrament
venerate we on our knees;
let the ancient liturgy
yield its place to this new rite;
let our faith redeem the failure
of our darkened sense.
To Begetter and Begotten
praise and joyful song,
salutation, honor, power,
blessings manifold;
and to Him from both proceeding
let our equal praise be told.
Thomas wrote almost as much as Albert, in a life little more than half as long. He composed commentaries on the Sentences of Peter Lombard, on the Gospels, Isaiah, Job, Paul; on Plato’s Timaeus, on Boethius and Pseudo-Dionysius; on Aristotle’s Organon, Of Heaven and Earth, Of Generation and Corruption, Meteorology, Physics, Metaphysics, On the Soul, Politics, Ethics-, quaestiones disputatae—On Truth, On Power, On Evil, On the Mind, On Virtues, etc.; quodlibeta discussing points raised at random in university sessions; treatises On the Principles of Nature, On Being and Essence, On the Rule of Princes, On the Occult Operations of Nature, On the Unity of the Intellect, etc.; a four-volume Summa de vertíate catholicae fidei contra Gentiles (1258–60), a twenty-one-volume Summa theologica (1267–73), and a Compendium theologiae (1271–3). Thomas’ published writings fill 10,000 double-column folio pages.
The Summa contra Gentiles, or Summary of the Catholic Faith Against the Pagans, was prepared at the urging of Raymond of Peñafort, General of the Dominican Order, to aid in the conversion of Moslems and Jews in Spain. Therefore Thomas in this work argues almost entirely from reason, though remarking sadly that “this is deficient in the things of God.”68 He abandons here the Scholastic method of disputation, and presents his material in almost modern style, occasionally with more acerbity than befitted him whom posterity would call doctor angelicus and seraphicus. Christianity must be divine, he thinks, because it conquered Rome and Europe despite its unwelcome preaching against the pleasures of the world and the flesh; Islam conquered by preaching pleasure and by force of arms.69 In Part IV he frankly admits that the cardinal dogmas of Christianity cannot be proved by reason, and require faith in the divine revelation of the Hebrew and Christian Scriptures.
Thomas’ most extensive work, the Summa theologica, is addressed to Christians; it is an attempt to expound and to defend—from Scripture, the Fathers, and reason—the whole body of Catholic doctrine in philosophy and theology.* “We shall try,” says the Prologue, “to follow the things that pertain to sacred doctrine with such brevity and lucidity as the subject matter allows.” We may smile at this twenty-one-volume brevity, but it is there; this Summa is immense, but not verbose; its size is merely the result of its scope. For within this treatise on theology are full treatises on metaphysics, psychology, ethics, and law; thirty-eight treatises, 631 questions or topics, 10,000 objections or replies. The orderliness of argument within each question is admirable, but the structure of the Summa has received more praise than its due. It cannot compare with the Euclidean organization of Spinoza’s Ethics, or the concatenation of Spencer’s Synthetic Philosophy. The treatise on psychology (Part I, QQ. 75–94) is introduced between a discussion of the six days of creation and a study of man in the state of original innocence. The form is more interesting than the structure. Essentially it continues, and perfects, the method of Abélard as developed by Peter Lombard: statement of the question, arguments for the negative, objections to the affirmative, arguments for the affirmative from the Bible, from the Fathers, and from reason, and answers to objections. The method occasionally wastes time by putting up a straw man to beat down; but in many cases the debate is vital and real. It is a mark of Thomas that he states the case against his own view with startling candor and force; in this way the Summa is a summary of heresy as well as a monument of dogma, and might be used as an arsenal of doubt. We may not always be satisfied with the answers, but we can never complain that the Devil has had an incompetent advocate.
VI. THE THOMIST PHILOSOPHY
1. Logic
What is knowledge? Is it a divine light infused into man by God, without which it would be impossible? Thomas parts company at the very outset from Augustine, the mystics, the intuitionists: knowledge is a natural product, derived from the external corporeal senses and the internal sense called consciousness of the self. It is an extremely limited knowledge, for up to our time no scientist yet knows the essence of a fly;70 but within its limits knowledge is trustworthy, and we need not fret over the possibility that the external world is a delusion. Thomas accepts the Scholastic definition of truth as adequatio rei et intellectus—the equivalence of the thought with the thing.71 Since the intellect draws all its natural knowledge from the senses,72 its direct knowledge of things outside itself is limited to bodies—to the “sensible” or sensory world. It cannot directly know the super-sensible, meta-physical world—the minds within bodies, or God in His creation; but it may by analogy derive from sense experience an indirect knowledge of other minds, and likewise of God.73 Of a third realm, the supernatural—the world in which God lives—the mind of man can have no knowledge except through divine revelation. We may by natural understanding know that God exists and is one, because His existence and unity shine forth in the wonders and organization of the world; but we cannot by unaided intellect know His essence, or the Trinity. Even the knowledge of the angels is limited, for else they would be God.
The very limitations of knowledge indicate the existence of a supernatural world. God reveals that world to us in the Scriptures. Just as it would be folly for the peasant to consider the theories of a philosopher false because he cannot understand them, so it is foolish for man to reject God’s revelation on the ground that it seems at some points to contradict man’s natural knowledge. We may be confident that if our knowledge were complete there would be no contradiction between revelation and philosophy. It is wrong to say that a proposition can be false in philosophy and true in faith; all truth comes from God and is one. Nevertheless it is desirable to distinguish what we understand through reason and what we believe by faith;74 the fields of philosophy and ideology are distinct. It is permissible for scholars to discuss among themselves objections to the faith, but “it is not expedient for simple people to hear what unbelievers have to say against the faith,” for simple minds are not equipped to answer.75 Scholars and ph
ilosophers, as well as peasants, must bow to the decisions of the Church; “we must be directed by her in all things”;76 for she is the divinely appointed repository of divine wisdom. To the pope belongs the “authority to decide matters of faith finally, so that they may be held by all with unshaken belief.”77 The alternative is intellectual, moral, and social chaos.
2. Metaphysics
The metaphysics of Thomas is a complex of difficult definitions and subtle distinctions, on which his theology is to rest.
1. In created things essence and existence are different. Essence is that which is necessary to the conception of a thing; existence is the act of being. The essence of a triangle—that it is three straight lines enclosing a space—is the same whether the triangle exists or is merely conceived. But in God essence and existence are one; for His essence is that He is the First Cause, the underlying power (or, as Spinoza would say, substantia) of all things; by definition He must exist in order that anything else should be.
2. God exists in reality; He is the Being of all beings, their upholding cause. All other beings exist by analogy, by limited participation in the reality of God.
3. All created beings are both active and passive—i.e., they act and are acted upon. Also, they are a mixture of being and becoming: they possess certain qualities, and may lose some of these and acquire others—water may be warmed. Thomas denotes this susceptibility to external action or internal change by the term potentia—possibility. God alone has no potentia or possibility; He cannot be acted upon, cannot change; He is actus purus, pure activity; pure actuality; He is already everything that He can be. Below God all entities can be ranged in a descending scale according to their greater “possibility” of being acted upon and determined from without. So man is superior to woman because “the father is the active principle, while the mother is a passive and material principle; she supplies the formless matter of the body, which receives its form through the formative power that is in the semen of the father.”78