Now, it will be observed, says the extreme eugenist, that these rules hold no matter whether the children develop in the city or in the country, in moist climate or dry, under conditions of good nutrition or of poor. And what is true of eye color he would maintain is true for skin and hair color, for stature, for abnormal fingers and toes, for diseases of various sorts. Even criminals, like poets and artists, are born and not made. It is not poor conditions that create insanity, but poor blood; not the germ of tuberculosis, but non-resistant protoplasm that causes death from consumption.
Thus the two schools of euthenics and eugenics stand opposed, each viewing the other unkindly. Against eugenics it is urged that it is a fatalistic doctrine and deprives life of the stimulus toward effort. Against euthentics the other side urges that it demands an endless amount of money to patch up conditions in the vain effort to get greater efficiency. Which of the two doctrines is true?
The thoughtful mind must concede that, as is so often the case where doctrines are opposed, each view is partial, incomplete and really false. The truth does not exactly lie between the doctrines; it comprehends them both. What a child becomes is always the resultant of two sets of forces acting from the moment the fertilized egg begins its development—one is the set of internal tendencies and the other is the set of external influences. What the result of an external influence —a particular environmental condition—shall be depends only in part upon the nature of the influence; it depends also upon the internal nature of the reacting protoplasm.
I have two dogs, a fox terrier, and a bird dog. They come upon a wounded bird. The terrier sniffs at it and passes it by, but the retriever picks it up and carries it for a time in its mouth. Is it simply the wounded bird that determines the retriever's action? Clearly no, since the bird did not cause the same response in the terrier. Is it alone the nature of the retriever that determined the carrying; no, since he would not similarly carry a stone. The result is due to the bird acting on the peculiar constitution of the retriever. So, in general, any human behavior is the resultant of the specific stimulus and the specific nature of the reacting protoplasm. Development is a form of behavior and how a child shall develop physically, mentally and morally is determined not by conditions alone, not by blood alone, but by conditions and blood; by the nature of the environment and the nature of the protoplasm.
This principle may be applied generally and it holds true even in diseases. It is an incomplete statement to say that the tubercle bacillus is the cause of tuberculosis, or alcohol the cause of delirium tremens. Experience proves it, for not all drunkards have delirium and not all that harbor the tubercle bacillus die of consumption—else we must all