Before the opening of the economic age, when the imagination glowed with all the passion of religious enthusiasm, the monks who built the abbeys of Cluny and Saint Denis took no thought of money, for it regarded them not. Sheltered by their convents, their livelihood was assured; their bread and their robe were safe; they pandered to no market, for they cared for no patron. Their art was not a chattel to be bought, but an inspired language in which they communed with God, or taught the people, and they expressed a poetry in the stones they carved which far transcended words. For these reasons Gothic architecture, in its prime, was spontaneous, elevated, dignified, and pure.
The advent of portraiture has usually been considered to portend decay, and rightly, since the presence of the portrait demonstrates the supremacy of wealth. A portrait can hardly be the ideal of an enthusiast, like the figure of a god, for it is a commercial article, sold for a price, and manufactured to suit a patron’s taste; were it made to please the artist, it might not find a buyer. When portraits are fashionable, the economic period must be well advanced. Portraiture, like other economic phenomena, blossomed during the Renaissance, and it was then also that the artist, no longer shielded by his convent or his guild, stood out to earn his living by the sale of his wares, like the Venetian merchants whom he met on the Rialto, whose vanity he flattered, and whose palaces he adorned. From the sixteenth century downward, the man of imagination, bereft of the economic instinct, has starved.
This mercenary quality forms the gulf which has divided the art of the middle ages from that of modem times — a gulf which cannot be bridged, and which has broadened with the lapse of centuries, until at last the artist, like all else in society, has become the creature of a commercial market, even as the Greek was sold as a slave to the plutocrat of Rome. With each invention, with each acceleration of movement, prose has more completely supplanted poetry, while the economic intellect has grown less tolerant of any departure from those representations of nature which have appealed to the most highly gifted of the monied type among successive generations. Hence the imperiousness of modem realism.
Thus the history of art coincides with the history of all other phenomena of life, for experience has demonstrated that, since the Reformation, a school of architecture, like the Greek or Gothic, has become impossible. No such school could exist in a society where the imagination had decayed, for the Greek and Gothic represented imaginative ideals. In an economic period, like that which has followed the Reformation, wealth is the form in which energy seeks expression: therefore, since the close of the fifteenth century, architecture has reflected money.
Decade by decade for some four hundred years, these phenomena have grown more sharply marked in Europe, and, as consolidation apparently nears its climax, art seems to presage approaching disintegration.
(Brooks Adams, The Law of Civilization and Decay. London: Swan Sonnenschein, 1895, pp. 293–295).