As we have grown into fuller social life, we have slowly and experimentally, painfully and expensively, discovered what kind of man was the best social factor. The type of a satisfactory member of society to-day is a man self-controlled, kind, gentle, strong, wise, brave, courteous, cheerful, true. In the Middle Ages, strong, brave, and true would have satisfied the demands of the time. We now require for our common good a larger range of qualities, a more elaborate moral organization. All this is a simple, evolutionary process of social life, and should have involved no more confusion, effort, and pain than any other natural process. But the moral development of humanity is a most tempestuous and contradictory field of study. Some virtues we have developed in orderly fashion, hardly recognizing that they were virtues, because they came so easily into use. Accuracy and punctuality are qualities which were unknown to the savage, because they were not needed in his business. They have been developed in us, because they were required, and so have been gradually assumed under pressure of economic necessity. Obedience, even in its extreme form of self-sacrifice, has been produced in the soldier; and no quality is more altruistic, more unnatural, or more difficult of adoption by the sturdy individual will. The common, law-abiding citizen does not consider himself a hero; yet he is manifesting a high degree of social virtue, often at great personal sacrifice. But in other virtues we have not progressed so smoothly. In the ordinary economic relations of life, and in our sex-relations, we are distinguished by peculiar and injurious qualities. Our condition may be described as consisting of a tenacious survival of qualities which we ought, on every ground of social good, to have long since outgrown; and an incessant struggle between these rudimentary survivals and the normal growth. This it is which has so forcibly assailed our consciousness since its awakening, and which we call the contest between good and evil. We have felt within ourselves the pull of diverse tendencies,—the impulse to do what was immediately good for ourselves, but which our growing social sense knew was bad for the community, and therefore wrong; and the impulse to do what might be immediately bad for ourselves, but which the same social sense knew was good for the community, and therefore right. This we felt, and cast about in our minds for an explanation of the way we behaved: we knew it was peculiar. The human brain is an organ that must have an explanation, if it has to make one. We made one.