Aristotle to prompt it.  Neither his Church nor the architect’s church was a sketch, but a completely studied structure.  Every relation of parts, every disturbance of equilibrium, every detail of construction was treated with infinite labour, as the result of two hundred years of experiment and discussion among thousands of men whose minds and whose instincts were acute, and who discussed little else.  Science and art were one.  Thomas Aquinas would probably have built a better cathedral at Beauvais than the actual architect who planned it; but it is quite likely that the architect might have saved Thomas some of his errors, as pointed out by the Councils of 1276.  Both were great artists; perhaps in their professions, the greatest that ever lived; and both must have been great students beyond their practice.  Both were subject to constant criticism from men and bodies of men whose minds were as acute and whose learning was as great as their own.  If the Archbishop of Canterbury and the Bishop of Paris condemned Thomas, the Bernardines had, for near two hundred years, condemned Beauvais in advance.  Both the “Summa Theologiae” and Beauvais Cathedral were excessively modern, scientific, and technical, marking the extreme points reached by Europe on the lines of scholastic science.  This is all we need to know.  If we like, we can go on to study, inch by inch, the slow decline of the art.  The essence of it—­the despotic central idea—­was that of organic unity both in the thought and the building.  From that time, the universe has steadily become more complex and less reducible to a central control.  With as much obstinacy as though it were human, it has insisted on expanding its parts; with as much elusiveness as though it were feminine, it has evaded the attempt to impose on it a single will.  Modern science, like modern art, tends, in practice, to drop the dogma of organic unity.  Some of the mediaeval habit of mind survives, but even that is said to be yielding before the daily evidence of increasing and extending complexity.  The fault, then, was not in man, if he no longer looked at science or art as an organic whole or as the expression of unity.  Unity turned itself into complexity, multiplicity, variety, and even contradiction.  All experience, human and divine, assured man in the thirteenth century that the lines of the universe converged.  How was he to know that these lines ran in every conceivable and inconceivable direction, and that at least half of them seemed to diverge from any imaginable centre of unity!  Dimly conscious that his Trinity required in logic a fourth dimension, how was the schoolman to supply it, when even the mathematician of to-day can only infer its necessity?  Naturally man tended to lose his sense of scale and relation.  A straight line, or a combination of straight lines, may have still a sort of artistic unity, but what can be done in art with a series of negative symbols?  Even if the negative were continuous, the artist might