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.