Max Müller, the Hindoos also struggled with the problem of making a square altar of the same size as a round one. In Egypt, geometry found its stimulus from the need of parcelling out the land fertilized by the Nile. The progress of architecture also increased knowledge of mathematics and physics. The great European cathedrals were built before scientific works upon architecture appeared. It is said that the needs of Alexander's campaigns in Persia contributed to the study of mathematics and physics. And the desire to save human life has always been a great incentive to the study of biology. These are simply a few illustrations of the kind of stimuli which have been most potent in the advancement of science.

After science has once gained a start, however, if social conditions are favorable, it will progress even without the immediate incentive of a practical need. As knowledge advances men begin to recognize its general value and try to extend it in every direction, believing in its ultimate, if not in its immediate, usefulness to mankind. This is science for the sake of science and is well exemplified in the present period of scientific development. Such a method of increasing knowledge is never purely arbitrary however. Not all forms of truth are considered of the same value at any given epoch. Even if scientists have not always in view some practical end, they are more likely to be interested in those departments of knowledge which have a bearing upon the immediate needs of their epoch. It will be observed, therefore, that this last influence, science for the sake of science, is not wholly separated from the preceding one, science for the sake of art, although in it a new motive is present. In addition to the need of solving an immediate problem, the recognition of the value of all positive knowledge becomes a new incentive to its further advancement.

Physical Conditions Favorable to the Development of Science. After this brief enumeration of the individual causes of the progress of science, we may turn to a consideration of the external conditions under which the pursuit of science is most likely to flourish. Science is more likely to advance, at least after a start has been made, in cold or in temperate climates

1 Origin of Religion, p. 142.

than in warm climates. According to Professor Cattell's "Study of Eminent Men," France has produced the largest number of scientists of any country, and England the next largest. This order is true not only in the absolute number, but also in the percentages of the total numbers of eminent men. Italy surpasses all countries in its proportionate number of artists. If the ancient civilizations were included in this comparison, the supremacy of the North would not be so evident; but it is hardly fair to include the ancient civilizations, for when they were flourishing societies in the northern countries had not matured. When northern societies did develop they produced their quota of scientists, though they failed to produce their proportionate number of artists.

The chief explanation of the advantage which cold countries have in the development of science is to be found in their greater needs. The environment is harder to subdue and at the same time man's requirements are greater, hence there is a continual incentive to improve the useful arts; and the attempt to improve arts is, as has already been said, the most important stimulus to the advancement of science. In addition to its greater needs, life in northern countries seems somewhat better adapted to the development of a thoughtful people. In southern countries social intercourse is more continuous and conditions are therefore less favorable for concentration. In northern countries more time is spent within doors, and social intercourse is interspersed with periods of isolation; and this condition is most favorable to the development of new ideas. Too isolated a life, however, would furnish no impetus for new ideas. Of course the desirable balance between the social and the secluded life may in particular cases occur in warm countries, but ordinarily physical conditions seem less favorable there than in colder countries.

Social Conditions Favorable to the Development of Science. Physical conditions are, however, less potent than social conditions in stimulating the advancement of science, as well as that of art. Three conditions of social life may be mentioned as especially important in preparing the way for scientific development. First, society should be far enough advanced in numbers and in wealth to have evolved a class that can devote its time to

intellectual pursuits. This condition is brought about comparatively early in society by the caste or class system, and later is made much more effective by division of labor. New Societies cultivate science but little, because they have neither produced a leisure class nor have they extended the system of division of labor far enough to permit individuals to devote their whole time to scientific pursuits. Secondly, a society should be active, for such a society undertakes new enterprises and stimulates science through the medium of the arts. Dormant societies, such as China and India, are satisfied with past achievements in knowledge; but when such societies reawaken, as has Japan, they feel the need of devoting themselves to the acquisition and extension of knowledge. Thirdly, social conditions should be of a kind that will enable man to emancipate himself from tradition. This is a different thing from what is commonly understood by freedom of thought. There are certain conditions in which men seem incapable of thinking outside of traditional ways, while under a different environment they may show great mental vigor in the face of severe persecution. Inasmuch as rigidly prescribed beliefs in society are usually due to the authority exercised by religion, emancipation from theological restrictions ordinarily precedes periods of mental activity. History gives us two well-marked periods of scientific advance, the Greek period of scientific thought, and the modern period beginning in the sixteenth century; and both movements began under similar circumstances. In both cases emancipation from theological dogmas preceded scientific activity, and this emancipation was accomplished by the stimulating effects of geographical discoveries. In Greece many of the old religious myths were actually disproved by these geographical discoveries, while others were undermined by the enlarged vision resulting from them. Similarly in the modern period intellectual life was greatly quickened by the discovery of America and the circumnavigation of the globe; and the authority of the church was weakened because of its strong opposition to the Copernican system. In 1616 the Inquisition issued an edict, which has never been repealed, declaring that to suppose the sun the center of the solar system was false and contrary to the Scriptures. It is

true that in the modern period before the discoveries were made, society was by no means stagnant; in fact the discoveries themselves were due to an awakening of intellect which may be traced to several sources, the chief of which was doubtless the travel and trade resulting from the crusades. Traced back to their sources, therefore, it will be seen that religious superstitions were themselves responsible for the movement which finally exterminated them. If, as a third period of scientific growth, we take into account the intellectual development of the Arabians, we shall find that this also was preceded by extended migrations and conquests, which affected greatly the religious beliefs of the Mohammedan conquerors. The whole intellectual attitude of the Saracens changed after their conquest of Africa. Although in the three cases just cited geographical discoveries were responsible for the change in mental attitude, no one agency can be held responsible in all cases for the emancipation of the mind. Where the forces of conservatism are very strong, a powerful social upheaval may be necessary to prepare the way for the reception of new truths. If, however, the intellectual condition is less rigid, milder changes may serve to stimulate thought. After scientific development has once begun, the resulting succession of new truths themselves offer the best security against the excessive influences of tradition.

Ordinarily an active society will free itself from the bonds of tradition; but this does not always happen, as is evidenced by the history of Spain during the period of intellectual activity which followed the geographical discoveries. Spain was an active country from the 14th to the 16th 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.

The most important stimulus to the development of the mind, according to Lester F. Ward, has been the formation of the system of caste, because it produced a leisure class. A caste system may certainly be advantageous in the early stages of mental development; but a society under its domination is likely to become conservative in an attempt to safeguard the interests of the privileged class. And when a caste system becomes rigid and traditional, its usefulness is gone. When the leisure class is also the priestly class, usually it does perform the service of 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 then a caste system has many disadvantages, and at no time is it as efficient in advancing knowledge as the system of division of labor.

Inasmuch as both science and art frequently respond to the same general conditions, it may be supposed that all conditions favoring the two are sufficiently alike to cause them to develop together. But this does not always happen. 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 architecture, literature, and science flourished simultaneously. In Italy, however, scientific activity followed art by at least a generation and was relatively less important. And in Spain science was hardly recognized when art and letters were cultivated brilliantly. Furthermore in Greece science developed at a considerably later period than art; but, on the other hand, in modern times science has made wonderful progress, while the achievement of art has been insignificant. The attainment of wealth and leisure is desirable for the development both of art and of science, and freedom from interference is essential for the best interests of both; but other circumstances may determine whether the intellect or the emotions shall 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; and a society may encourage the fine arts without developing the useful arts, and hence not give any special stimulus to the advancement of science. A luxury-loving class which may patronize the fine arts is likely to be conservative and intolerant of revolutionary discoveries. An underlying seriousness in the social life conditions scientific activity, and this was entirely lacking in Spain in the 17th century. On the other hand, young active societies are likely to show an interest in science before they make any headway in the production of the fine arts. Economic conditions which produce luxury, with social conditions which