The fact that a decline in human fertility and a falling birth rate are most noticeable in the relatively prosperous countries is a proof that it does not proceed from economic causes; but is due rather to the spread of the doctrine that it is permissible to restrict or control birth. In such countries as the United States, England and Australasia, where the standards of human comfort and living are notoriously high, the decline in the birth rate has been most noticeable. On the other hand, we find perhaps the greatest decline in the birth rate in France, a country where the general well-being probably reaches a lower depth in the community than in any other part of Europe. A comparison of the birth rates of France and of Ireland, for example, offer a valuable illustration of the point under consideration. In France, more than half the women who have reached the age of nubility are married; in Ireland, generally speaking, less than a third. In both countries the crude birth rate is far below that in other European lands. Yet the fertility of the Irish wife exceeded that of her French compeer by 44 per cent in 1880, and by no less than 84 per cent in 1900. And since that time the prolificity of the Irish mother has so increased that she is now, approximately speaking, inferior only to the Dutch or Finnish mother in this respect. In general, in any country where we find a diminished prolificity a falling off of childbirth _unaccompanied_ by a decrease in the number of marriages occurring at the reproductive ages, we may attribute this decrease to _voluntary restriction of childbearing_ on the part of the married, or in other words, to the prevalence of "birth control." This incidentally, is not a theoretical statement, but one supported by the almost unanimous medical opinion in all countries. Everywhere and especially here in our own United States, we find evidence of the extensive employ of "birth control" measures to prevent that normal development of family life which underlies the vigor and racial power of every nation. These preventive measures which arbitrarily control human birth had long been in use in France with results which, especially since the war, have been frequently and publicly deplored in the press, and have led the French Government to offer substantial rewards to encourage the propagation of large families. From France the preventive practices of "birth control" had spread, after 1870, over nearly all the countries of western Europe, to England and to the United States; though they are not as much apparent in those countries where the Roman Church has a strong hold on the people.