It will be agreed that it is difficult to obtain anything logical or coherent from the total of different religious moralities. As regards the sexual question, so-called divine commandments, such as those of monogamy and polygamy, directly contradict each other.

For this reason, we will leave the so-called revealed morality to the priests of diverse religions who pretend to have received them directly from God, and will confine ourselves to the study of purely human morality. This should never be based on any dogmatic formula, like the above on their religious dogmas; it must be evolved from the natural conditions of human life.

Morality and Hygiene.—Morality is intimately connected with hygiene, and wherever there appears to be a contradiction between hygiene and ethics this is due to the fact that individual hygiene has only been considered, and not public or social hygiene—that is the hygiene of the race. It is the duty of the medical profession to place social above individual hygiene, to subordinate the hygienic welfare of the individual to that of society. A contradiction may exist between individual morality and hygiene, never between social morality and hygiene.

Definition of Morality.—How can we define morality or ethics? Liberated as far as possible from all hypothesis, ethics is theoretically the study of what is good or bad in human actions, and practically, as regards morality, the duty of doing good and avoiding evil. But this is hardly explicit, for what do we understand by good and evil? Not only do some consider good what others consider evil, but the words which Goethe puts into the mouth of the devil (in "Faust")—that while wishing evil he often did good—will always be true. This gives a faithful representation of the deplorable want of adaptation which exists between the good and evil effects of our actions on the one hand, and the goodness or wickedness of our motives on the other hand. The inverse is also true, for good intentions often have evil results. We must, therefore, carefully distinguish between the ethical motives of the good and bad effects of an action.

If we continue our analysis we shall discover that the same action may be good for one and bad for another. When a wolf devours a lamb, it is good for the wolf but bad for the lamb. We cannot live without destroying other lives, animal or vegetable. The money we earn comes out of the pockets of others without their always obtaining a corresponding profit, and so on. Morality is thus relative, and we have not the faculty of discovering anything which is absolutely good or absolutely bad in itself.

All that men can expect by mutual exchange of their wisdom and good will is to do as little evil and as much good as possible, that is to say, to diminish the amount of their physical and psychic ills by improving their mutual conditions of existence, and thus increasing the amount of good. Even this is only possible by limiting the ideas of good and evil almost exclusively to humanity, trampling on the conditions of existence and the development of other beings, or at least concerning ourselves with them only as far as they are useful to us.

Further, we have seen that it is very difficult to extend the conception of social welfare to all the living races of humanity, for some of them are at the same time so fecund and so inferior in quality, that if they were allowed to multiply around us without any precaution they would soon starve and supplant us. Then the barbarity of their lower instincts (vide weight of brain in different races at end of Chapter VI) would soon take the upper hand and become general, as the negroes of Hayti have shown us by a lesson which is worthy of our attention.

Therefore, an exaggeration of moral sentiments, resting on a false basis, would have the positive result of striking a fatal blow at our social morality, slowly built up during hundreds or thousands of years.

Lastly, the same action may first of all do evil and afterwards good, for example, a painful lesson; or vice versa, as in the satisfaction of a gluttonous appetite.

Morality can only be Relative.—It follows from these considerations that our moral duties can only be relative, and cannot bind us in the same way nor in the same degree to all living beings, not even to all men, if we would avoid sacrificing what is lofty to what is vile. In theory, the definition of human morality will consist in a just and scientific definition of social welfare and the exigencies which it imposes on individuals, in order that the latter do not do evil in attempting to do good. In practice, it will be the general effort made to develop successfully this social welfare by the aid of individual will. This presupposes in the first place education of the will, the dispositions to useful work, and the altruistic sentiments of each individual. It is neither theoretical dogma nor preaching, but action and example which make for the education of man.