Theologians, like architects, were supposed to receive their Church complete in all its lines; they were modern judges who interpreted the laws but never invented it. Saint Thomas merely selected between disputed opinions, but he allowed himself to wander very far afield, indeed, in search of opinions to dispute. The field embraced all that existed, or might have existed, or could never exist. The immense structure rested on Aristotle and Saint Augustine at the last, but as a work of art it stood alone, like Rheims or Amiens Cathedral, as though it had no antecedents. Then, although, like Rheims, its style was never meant to suit modern housekeeping and is ill-seen by the Ecole des Beaux Arts, it reveals itself in its great mass and intelligence as a work of extraordinary genius; a system as admirably proportioned as any cathedral and as complete; a success not universal either in art or science.
Saint Thomas's architecture, like any other work of art, is best studied by itself as though he created it outright; otherwise a tourist would never get beyond its threshold. Beginning with the foundation which is God and God's active presence in His Church, Thomas next built God into the walls and towers of His Church, in the Trinity and its creation of mind and matter in time and space; then finally he filled the Church by uniting mind and matter in man, or man's soul, giving to humanity a free will that rose, like the fleche, to heaven. The foundation—the structure—the congregation— are enough for students of art; his ideas of law, ethics, and politics; his vocabulary, his syllogisms, his arrangement are, like the drawings of Villard de Honnecourt's sketch-book, curious but not vital. After the eleventh-century Romanesque Church of Saint Michael came the twelfth-century Transition Church of the Virgin, and all merged and ended at last in the thirteenth-century Gothic Cathedral of the Trinity. One wants to see the end.
The foundation of the Christian Church should be—as the simple deist might suppose—always the same, but Saint Thomas knew better. His foundation was Norman, not French; it spoke the practical architect who knew the mathematics of his art, and who saw that the foundation laid by Saint Bernard, Saint Victor, Saint Francis, the whole mystical, semi-mystical, Cartesian, Spinozan foundation, past or future, could not bear the weight of the structure to be put on it. Thomas began by sweeping the ground clear of them. God must be a concrete thing, not a human thought. God must be proved by the senses like any other concrete thing; "nihil est in intellectu quin prius fuerit in sensu"; even if Aristotle had not affirmed the law, Thomas would have discovered it. He admitted at once that God could not be taken for granted.
The admission, as every boy-student of the Latin Quarter knew, was exceedingly bold and dangerous. The greatest logicians commonly shrank from proving unity by multiplicity. Thomas was one of the greatest logicians that ever lived; the question had always been at the bottom of theology; he deliberately challenged what every one knew to be an extreme peril. If his foundation failed, his Church fell. Many critics have thought that he saw dangers four hundred years ahead. The time came, about 1650-1700, when Descartes, deserting Saint Thomas, started afresh with the idea of God as a concept, and at once found himself charged with a deity that contained the universe; nor did the Cartesians—until Spinoza made it clear—seem able or willing to see that the Church could not accept this deity because the Church required a God who caused the universe. The two deities destroyed each other. One was passive; the other active. Thomas warned Descartes of a logical quicksand which must necessarily swallow up any Church, and which Spinoza explored to the bottom. Thomas said truly that every true cause must be proved as a cause, not merely as a sequence; otherwise they must end in a universal energy or substance without causality—a source.
Whatever God might be to others, to His Church he could not be a sequence or a source. That point had been admitted by William of Champeaux, and made the division between Christians and infidels. On the other hand, if God must be proved as a true cause in order to warrant the Church or the State in requiring men to worship Him as Creator, the student became the more curious—if a churchman, the more anxious—to be assured that Thomas succeeded in his proof, especially since he did not satisfy Descartes and still less Pascal. That the mystics should be dissatisfied was natural enough, since they were committed to the contrary view, but that Descartes should desert was a serious blow which threw the French Church into consternation from which it never quite recovered.
"I see motion," said Thomas: "I infer a motor!" This reasoning, which may be fifty thousand years old, is as strong as ever it was; stronger than some more modern inferences of science; but the average mechanic stated it differently. "I see motion," he admitted: "I infer energy. I see motion everywhere; I infer energy everywhere." Saint Thomas barred this door to materialism by adding: "I see motion; I cannot infer an infinite series of motors: I can only infer, somewhere at the end of the series, an intelligent, fixed motor." The average modern mechanic might not dissent but would certainly hesitate. "No doubt!" he might say; "we can conduct our works as well on that as on any other theory, or as we could on no theory at all; but, if you offer it as proof, we can only say that we have not yet reduced all motion to one source or all energies to one law, much less to one act of creation, although we have tried our best." The result of some centuries of experiment tended to raise rather than silence doubt, although, even in his own day, Thomas would have been scandalized beyond the resources of his Latin had Saint Bonaventure met him at Saint Louis's dinner-table and complimented him, in the King's hearing, on having proved, beyond all Franciscan cavils, that the Church Intellectual had necessarily but one first cause and creator—himself.
The Church Intellectual, like the Church Architectural, implied not one architect, but myriads, and not one fixed, intelligent architect at the end of the series, but a vanishing vista without a beginning at any definite moment; and if Thomas pressed his argument, the twentieth-century mechanic who should attend his conferences at the Sorbonne would be apt to say so. "What is the use of trying to argue me into it? Your inference may be sound logic, but is not proof. Actually we know less about it than you did. All we know is the thing we handle, and we cannot handle your fixed, intelligent prime motor. To your old ideas of form we have added what we call force, and we are rather further than ever from reducing the complex to unity. In fact, if you are aiming to convince me, I will tell you flatly that I know only the multiple, and have no use for unity at all."
In the thirteenth century men did not depend so much as now on actual experiment, but the nominalist said in effect the same thing. Unity to him was a pure concept, and any one who thought it real would believe that a triangle was alive and could walk on its legs. Without proving unity, philosophers saw no way to prove God. They could only fall back on an attempt to prove that the concept of unity proved itself, and this phantasm drove the Cartesians to drop Thomas's argument and assert that "the mere fact of having within us the idea of a thing more perfect than ourselves, proves the real existence of that thing." Four hundred years earlier Saint Thomas had replied in advance that Descartes wanted to prove altogether too much, and Spinoza showed mathematically that Saint Thomas had been in the right. The finest religious mind of the time—Pascal— admitted it and gave up the struggle, like the mystics of Saint- Victor.
Thus some of the greatest priests and professors of the Church, including Duns Scotus himself, seemed not wholly satisfied that Thomas's proof was complete, but most of them admitted that it was the safest among possible foundations, and that it showed, as architecture, the Norman temper of courage and caution. The Norman was ready to run great risks, but he would rather grasp too little than too much; he narrowed the spacing of his piers rather than spread them too wide for safe vaulting. Between Norman blood and Breton blood was a singular gap, as Renan and every other Breton has delighted to point out. Both Abelard and Descartes were Breton. The Breton seized more than he could hold; the Norman took less than he would have liked.
God, then, is proved. What the schools called form, what science calls energy, and what the intermediate period called the evidence of design, made the foundation of Saint Thomas's cathedral. God is an intelligent, fixed prime motor—not a concept, or proved by concepts;—a concrete fact, proved by the senses of sight and touch. On that foundation Thomas built. The walls and vaults of his Church were more complex than the foundation; especially the towers were troublesome. Dogma, the vital purpose of the Church, required support. The most weighty dogma, the central tower of the Norman cathedral, was the Trinity, and between the Breton solution which was too heavy, and the French solution which was too light, the Norman Thomas found a way. Remembering how vehemently the French Church, under Saint Bernard, had protected the Trinity from all interference whatever, one turns anxiously to see what Thomas said about it; and unless one misunderstands him,—as is very likely, indeed, to be the case, since no one may even profess to understand the Trinity,—Thomas treated it as simply as he could. "God, being conscious of Himself, thinks Himself; his thought is Himself, his own reflection in the Verb—the so-called Son." "Est in Deo intelligente seipsum Verbum Dei quasi Deus intellectus." The idea was not new, and as ideas went it was hardly a mystery; but the next step was naif:—God, as a double consciousness, loves Himself, and realizes Himself in the Holy Ghost. The third side of the triangle is love or grace.