But I believe that the principles here set forth are able to show us how such women may remain feminine, and may discharge characteristically feminine functions in society, even though physical motherhood be denied them. The _racial_ importance of physical motherhood cannot be exaggerated, because it determines, as we have seen, not less than half the natural composition of future generations. But its _individual_ importance can easily be over-estimated, and that is an error which I have specially sought to avoid in this book, which is certainly an attempt to call or recall women to motherhood. It is not as if physical motherhood were the whole of human motherhood. Racially, it is the substantial whole; individually, it is but a part of the whole, and a smaller fraction in our species than in any humbler form of life. Everyone knows maiden aunts who are better, more valuable, completer mothers in every non-physical way than the actual mothers of their nephews and nieces. This is woman's wonderful prerogative, that, in virtue of her _psyche_, she can realize herself, and serve others, on feminine lines, and without a pang of regret or a hint anywhere of failure, even though she forego physical motherhood. This book, therefore, is a plea not only for Motherhood but for Foster-Motherhood--that is, Motherhood all-but-physical. In time to come the great professions of nursing and teaching will more and more engage and satisfy the lives and the powers of Virgin-Mothers without number. Let no woman prove herself so ignorant or contemptuous of great things as to suggest that these are functions beneath the dignity of her complete womanhood.