It is first the higher, refined spiritual civilization which brings with it a higher conception of marriage as the realization of the ideal, individual only-love. As Ludwig Stein justly remarks: “It was not in our own time that marriage first began to degenerate to the level of an economic idea. The converse, indeed, is true; the economic background of marriage, as it so clearly manifests itself among savage races, =first began to disappear in the course of the development of our own system of civilization, and therewith began also the liberation of mankind from the burden of metallic shackles=.”[179] At the same time, it cannot be denied that even at the present day the economic factor plays a very extensive part in the determination of marriage, although certainly not to the degree maintained by Buckle, who held that there was a fixed and definite relationship between the number of marriages and the price of corn.[180] Beyond question, economic considerations have a great influence upon the frequency of marriage. Many marriages, even to-day, are purely mercenary marriages; but still at the present time the qualities of intellect and emotion, quite apart from physical characteristics, have at least an equal share in the production of marriage. Only among the classes who feel it their duty to keep up a particular kind of appearance, among the upper-middle classes, the aristocracy, and among officers in the army, is the economic question the main determining influence in marriage. Well known, also, is the predominance of mercenary marriages among the Jews. One may be an enemy of mammonism, and still see the necessity for an economic regulation of conjugal relations in view of the expected offspring, of the altered conditions of life, of the increase in the household, and of the necessity for safeguarding personal independence and free development. Such economic considerations can harmonize perfectly with the demand for personal sympathy, and with the most intimate physical and spiritual harmony between husband and wife. Schmoller rightly places the most important advance of the modern family in this, that it becomes more and more transformed from a productive and business institute into an institute of moral life in common; that by the =limitation= of its economic purposes the nobler ideal must become more predominant, and the family become a richer soil for the cultivation of sympathetic sentiments.[181]