There is no subject on which religious teachers have dwelt more than upon marriage and the relation of the sexes, and it has been continually urged that the propagation of children is its first end. It is strange, however, to observe how almost absolutely in the popular ethics of Christendom such considerations as that which I have last mentioned have been neglected. If one of the most responsible things that a man can do is to bring a human being into the world, one of his first and most obvious duties is to do what he can to secure that it shall come into the world with a sound body and a sane mind. This is the best inheritance that parents can leave their children, and it is in a large degree within their reach. Immature marriage, excessive child-bearing, marriages of near relations, and, above all, marriages with some grave hereditary physical or mental disease or some great natural defect, may bring happiness to the parents, but can scarcely fail to entail a terrible penalty upon their children. It is clearly recognised that one of the first duties of parents to their children is to secure them in early life not only good education, but also, as far as is within their power, the conditions of a healthy being. But the duty goes back to an earlier stage, and in marriage the prospects of the unborn should never be forgotten. This is one of the considerations which in the ethics of the future is likely to have a wholly different place from any that it has occupied in the past. A kindred consideration, little less important and almost equally neglected in popular teaching, is that it is a moral offence to bring children into the world with no prospect of being able to provide for them. It is difficult to exaggerate the extent to which the neglect of these two duties has tended to the degradation and unhappiness of the world.