tion. But that is not always the case, as is shown by the history of Spain during the period of intellectual activity which followed the geographical discoveries. Spain was an active country from the fourteenth to the sixteenth centuries, but its activity was not sufficient to overcome its intellectual conservatism; and this seems to be the reason why Spain took no part in the scientific progress of that period.
Professor Ward thinks the most important stimulus to the development of the mind has been the formation of the system of caste, because it produced a leisure class. A caste system is certainly important in the early stages of mental development, but such a society is likely to become conservative in its attempt to safeguard the interests of the leisure class. And when a caste system becomes rigid and traditional its usefulness is gone. If the idle class is also a priestly class, it is usually of service in preserving knowledge, but the very tenacity with which it clings to old ideas prevents it from discovering or accepting new ones. In the long run, therefore, a caste system has many disadvantages, and at no time is it so efficient in the advancement of knowledge as the system of division of labor.
Some of the conditions which help to stimulate science are also favorable to the production of art and it may be thought that all conditions favoring the two are sufficiently alike to cause science and art to develop together. But such is not always the case. Art, literature, and science developed in much the same period in France, and the same is also true of the Netherlands. Literature and science developed together in England. In the Arabian civilization also architecture, literature and science flourished simultaneously. In Italy, however, scientific activity followed art by at least a generation and it was relatively much less important. And in Spain science was almost disregarded when art and letters were cultivated with brilliant results. Furthermore, in Greece science developed at a considerably later period than art, and again in modern times science has made wonderful progress with only moderate achievements in art. The attainment of wealth and leisure is desirable for the development of both art and science and freedom from interference is essential for the best interests of both; but other circumstances may determine whether the intellect or the emotions will develop more fully. A society which is very rigid in its intellectual beliefs may produce a high grade of art in giving expression to those beliefs; or a society may encourage the fine arts while it does not develop the useful arts and hence does not give a special stimulus to the advancement of science. A wealthy luxurious upper class which may patronize the fine arts is likely to be conservative and intolerant of revolutionary discoveries. Scientific activity requires an underlying seriousness in the social life; and this was entirely lacking in Spain, for example, in the seventeenth century. On the other