Of course, many of the obvious defects would be apparent in any environment, but where the reaction of inheritance and environment is subtler this is not true. It is only by "feeding out" that the stockman determines which strains of his cattle most readily lay on flesh; without trying it on the track the horseman has no test of the speed of his horse; and unless the dairyman tests the milk-producing qualities of his cows under the most favorable conditions, he has no true measure for selecting those by which he may expect to improve his herd. The rose may never bloom to perfection if it is too closely crowded by other plants—our best flowers need care and protection, because they are adapted only to a special environment. It may be urged that what we need is the virile plant that will assert itself in any environment; that we need the Lincolns and others who could attain to greatness without the aid of colleges or fellowships. But we can scarcely hope to establish at once a race of Lincolns, and it is as probable that the special environments will be as necessary for the higher types of man as they are for our specialized domesticated plants and animals. It is necessary to consider its reaction to the environment the test of the individual.
When we are able to distinguish the good inheritance from the bad, how shall we proceed to perpetuate the one and to eliminate the other? This is a matter which can be worked out only with care and patience. Measures which would disturb the fundamental relationships of society form no part of the conservative eugenic program. The extent to which certain influences, such as the church and popular belief, have been able to influence marriage in the past, lead us to hope that rational education may have a considerable influence in the future. Selective mating may also play a part, since there is a tendency for a person to select a mate who has in general similar tastes and ideals. I have no statistics at hand, but I am of the impression an investigation of the subject would show, for example, a relatively high correlation between the graduates of colleges who marry college graduates. So much as to the perpetuation of the good. As to the bad, the eugenist can here lay down definite plans, and such in fact are already in operation to some extent in certain states. If society is justified in ridding itself of the criminal, it is certainly justified in taking all precautions that he shall leave no descendants.
Our eugenic program is then first of all patient and persistent accumulation and study of the facts, and in the second place education, or extension—the bringing of those facts home to the people. We must be guarded in our statements and cautious in our proposals, for to raise antagonism over misunderstandings or small disputed points will only delay and impede progress. As eugenists—and we should all be eugenists—we must work patiently, impassionately, scientifically, but keeping ever before us as our guiding star a lofty and righteous ideal.