Nevertheless, the growth of Gothic architecture was rapid, so rapid that even in the fourteenth century it began to show symptoms of that swift decadence which is the Nemesis of facile success. The abuse of equilibrium, the excessive diminution of points of support--defects often aggravated by insecurity of foundation and exaggerated loftiness of structure--the poor quality of materials, and the faulty setting thereof due to empirical methods, the over-rapidity of execution caused by mistaken emulation, the dearth of funds consequent on social and political convulsions complicated by the miseries of war,--all these things joined hands for the extinction of a once resplendent art. But the initial cause of its ruin must be sought in its abandonment of antique traditions. These traditions had persisted uninterruptedly throughout the so-called Romanesque period, only to pave the way for a seductive art in novel form, which, casting aside the trammels of the past in obedience to the dictates of the moment, fell on decay as rapidly as it had risen to eminence. Dawning in the France of Louis the Fat, it reached its apogee under St. Louis, and was in full decadence before the close of the fifteenth century. The narrow limits assigned to us forbid not only detailed discussion of our great monuments, but even a summary of the most famous. We must be content to work out that theory of evolution already put forward by us in _L'Architecture Romane_. We propose merely to offer a synthesis of that architectural development which succeeded the so-called Romanesque epoch, from its birth in the twelfth to its extinction in the fifteenth century. And as the groined vault is, broadly speaking, the essential characteristic of so-called Gothic architecture, and the flying buttress one of its most interesting manifestations, we shall make a special study of their origin, their modifications, and their principal applications in connection with religious, monastic, military, and civil architecture. We shall dwell more particularly upon religious architecture as presenting the grandest and most obvious evidences of artistic progress, not in its admirable buildings alone, but in those masterpieces of painting and sculpture to which it gave birth in France. PART I RELIGIOUS ARCHITECTURE CHAPTER I THE INFLUENCE OF THE CUPOLA UPON SO-CALLED GOTHIC ARCHITECTURE _The cupola, in its symbolic aspect, was the germ, whence sprang an architectural system the revolutionary action of which upon art can scarcely be over-estimated._[2] [2] _L'Architecture Romane_, by Ed. Corroyer; Quantin, Paris, 1888.