As a result of exaggerating the above-mentioned phenomena certain theorists have imagined that ethics can be founded upon pure egotism. But this is a mistake. Without the altruistic impulses of sympathy and duty among its individual members no common social existence can thrive; on the contrary, it must degenerate. The power of the emotions in man is much too strong to allow of any other result. Any one who imagines that he is completely master of his emotions makes, if possible, a still greater mistake than one who avows that he has never lied, or that his actions are governed by free-will. All human morality is bound up with these impulses and emotions. Socialism, for instance, will become moral, or else it will not come to pass. Without the support of the social conscience of mankind it cannot become moral. Every effort must therefore be directed towards strengthening the social conscience. The falsity of the theory of absolute good and evil is demonstrated by the whole disposition of a world in which living creatures are designed to prey upon one another. When a spider devours a fly it is good for the spider and bad for the fly. The ethical value of the act itself is therefore purely relative. It is just the same with human ethics. To attempt to explain all the evil in the world by the sin of Adam is to attribute a miserable incapacity to God. The same holds true of the attempts of certain modern Protestants to set up the dogma of a progressive revelation, in order to bring the older dogmas into harmony with the theory of evolution and descent. All these halting exegeses are only new models of the artificial drags which theology seeks to impose upon the free research of science. Altruism and egotism stand only in relative opposition. Among ants and bees they are instinctively adjusted to one another with wonderful harmony, and are rarely, if ever, found in conflict. This result can and must be striven after by mankind, however great may be the difficulties presented by our hereditary nature. For its achievement a harmonious co-operation of the hereditary social conscience with reason and knowledge is absolutely necessary. I must briefly mention two other points. Firstly, morality and social or race hygiene become one and the same thing directly we include in our conception of hygiene a healthy condition of the brain or soul, and subordinate the individual hygiene to that of society in general. Then everything socially unhygienic is immoral, and everything immoral socially unhygienic. If, for instance, I ruin a healthy, active member of society, in order possibly to achieve the salvation of an incurably diseased criminal, I am committing, although from altruistic motives, an act which is injurious from the point of view both of ethics and social hygiene, and therefore evil and immoral.