It is often said that there can be no such thing as progress in art. At one time the arts flourish, at another they decay: but, as Whistler put it, art happens as men of genius happen; and men cannot make it happen. They cannot discover what circumstances favour art, and therefore they cannot attempt to produce those circumstances. There are periods of course in which the arts, or some one particular art, progress. One generation may excel the last; through several generations an art may seem to be rushing to its consummation. This happened with Greek sculpture and the Greek drama in the sixth and fifth centuries; with architecture and all kindred arts in western Europe in the twelfth and thirteenth centuries, and at the same time with many arts in China. It happened with painting and sculpture in Italy in the fourteenth and fifteenth centuries, with literature in England in the sixteenth century, with music in Germany in the eighteenth century and the beginning of the nineteenth. But in all these cases there followed a decline, often quite unconscious at the time and one of which we cannot discover the causes. Attempts are made by historians of the arts to state the causes; but they satisfy only those who make them, for they are, in fact, only statements of the symptoms of decline. They tell us what happened, not why it happened. And they all seem to point to two conclusions about the course of the arts, both of which would make us despair of any settled progress in them. The first is that the practice of any art by any particular people always follows a certain natural course of growth, culmination, and decay. At least it always follows this course where an art is practised naturally and therefore with success. Art in fact, in its actual manifestations, is like the life of an individual human being and subject to inexorable natural laws. It is born, as men are born, without the exercise of will; and in the same way it passes through youth, maturity, and old age. The second conclusion follows from this, and it is that one nation or age cannot take up an art where another has left it. That is where art seems to differ from science. The mass of knowledge acquired in one country can, if that country loses energy to apply or increase it, be utilized by another. But we cannot so make use of the art of the Greeks or of the Italian Renaissance or of our own Middle Ages. In the Gothic revival we tried to make use of the art of the Middle Ages and we failed disastrously. We imitated without understanding, and we could not understand because we were not ourselves living in the Middle Ages. Art, in fact, is always a growth of its own time which cannot be transplanted, and no one can tell why it grows in one time and among one people and not in another.