To begin with what is perhaps the oldest of these, though indeed scarcely entitled to the appellation of popular, let us assure ourselves once and for all that we are talking about a fact natural, innate, not acquired. The modern criticism of ancient notions of human nature, such as those expressed in the theologians' conception of "conscience," has inclined some to the view that our best feelings are indeed not at all innate. No one can for a moment analyze conscience without observing the immense disparity between the facts and the theologians' theory. And thus we are apt to fall into the opposite error of supposing that our impulses towards good action are entirely the products of education, training, public opinion, and so forth. Let the reader refer, for instance, to such a celebrated work as John Stuart Mill's "Utilitarianism," and it will be seen how wide of the mark it was possible for even a great thinker to go, when his ideas of mind were unguided by the light of evolution. Even in the greatest writer of that time not a syllable do we find as to the parental instinct. "As is my own belief," says Mill, "the moral feelings are not innate but acquired." Yet we have seen convincing evidence which teaches us that the moral feelings spring essentially from the root of the parental instinct, without which mankind could not continue for another generation, and than which there is nothing more fundamental and essential in any type of human nature that can persist. The importance of noting this can be clearly stated. We are here dealing with something which is not for us to implant, but which is already part of the plant, so to speak, and which it is for us to tend. Like other innate features of mankind, its transmission from generation to generation is notably independent of the effects of education, the effects of use and disuse. This is a difficult thing of which to persuade people, but it is the fact. Education, environment, training, opportunity, habit, public opinion, social prejudice--all these and such other influences may and do affect the maternal instinct in the individual for good or for evil. No fact is more certain or important, and that is precisely why we must study this instinct. But the effect upon the individual does not involve any effect upon the native constitution of the individual's children. From age to age the general facts and features of the human backbone persist. We do not expect to find notable differences between the generations in such a radical feature of our constitution, no matter what particular habits of posture, play, and the like we adopt. The maternal instinct is scarcely less fundamental; it is certainly no whit less essential for the species. It is the very backbone of our psychological constitution. Thus it is nonsense to assert that, for instance, women are becoming less motherly, if by this is meant that the maternal instinct is failing.