of activities, it is not sufficiently prospective, to make an existence in which ultimate satisfaction can be found. It brings its great moments, and then its times which are less great, which are unsatisfying because they are less great. It becomes, sooner or later, retrospective, a tomb of dead joys, not a well-spring of new life. This evil is inseparable from any purpose which is to be achieved in a single supreme emotion. The only adequate purposes are those which stretch out into the future, which can never be fully achieved, but are always growing, and infinite with the infinity of human endeavor. And it is only when love is linked to some infinite purpose of this kind that it can have the seriousness and depth of which it is capable.
For the great majority of men and women seriousness in sex relations is most likely to be achieved through children. Children are to most people rather a need than a desire: instinct is as a rule only consciously directed towards what used to lead to children. The desire for children is apt to develop in middle life, when the adventure of one's own existence is past, when the friendships of youth seem less important than they once did, when the prospect of a lonely old age begins to terrify, and the
