express at least a negation; but supposing that Omar’s kinetic analogy of the ball and the players turned out to be a scientific formula!—­supposing that the highest scientific authority, in order to obtain any unity at all, had to resort to the Middle Ages for an imaginary demon to sort his atoms!—­how could art deal with such problems, and what wonder that art lost unity with philosophy and science!  Art had to be confused in order to express confusion; but perhaps it was truest, so.

Some future summer, when you are older, and when I have left, like Omar, only the empty glass of my scholasticism for you to turn down, you can amuse yourselves by going on with the story after the death of Saint Louis, Saint Thomas, and William of Lorris, and after the failure of Beauvais.  The pathetic interest of the drama deepens with every new expression, but at least you can learn from it that your parents in the nineteenth century were not to blame for losing the sense of unity in art.  As early as the fourteenth century, signs of unsteadiness appeared, and, before the eighteenth century, unity became only a reminiscence.  The old habit of centralizing a strain at one point, and then dividing and subdividing it, and distributing it on visible lines of support to a visible foundation, disappeared in architecture soon after 1500, but lingered in theology two centuries longer, and even, in very old-fashioned communities, far down to our own time; but its values were forgotten, and it survived chiefly as a stock jest against the clergy.  The passage between the two epochs is as beautiful as the Slave of Michael Angelo; but, to feel its beauty, you should see it from above, as it came from its radiant source.  Truth, indeed, may not exist; science avers it to be only a relation; but what men took for truth stares one everywhere in the eye and begs for sympathy.  The architects of the twelfth and thirteenth centuries took the Church and the universe for truths, and tried to express them in a structure which should be final.  Knowing by an enormous experience precisely where the strains were to come, they enlarged their scale to the utmost point of material endurance, lightening the load and distributing the burden until the gutters and gargoyles that seem mere ornament, and the grotesques that seem rude absurdities, all do work either for the arch or for the eye; and every inch of material, up and down, from crypt to vault, from man to God, from the universe to the atom, had its task, giving support where support was needed, or weight where concentration was felt, but always with the condition of showing conspicuously to the eye the great lines which led to unity and the curves which controlled divergence; so that, from the cross on the fleche and the keystone of the vault, down through the ribbed nervures, the columns, the windows, to the foundation of the flying buttresses far beyond the walls, one idea controlled every line; and this is true of Saint