It has been wisely observed by the greatest of modern thinkers that mankind has progressed more rapidly in every other respect than in morality. Moral progress has not been rapid simply because the moral ideal has always been kept a little in advance of the humanly possible. Thousands of years ago the principles of morality were exactly the same as those which rule our lives to-day. We can not improve upon them; we can not even improve upon the language which expressed them. The most learned of our poets could not make a more beautiful prayer than the prayer which Egyptian mothers taught to their little children in ages when all Europe was still a land of savages. The best of the moral philosophy of the nineteenth century is very little of improvement upon the moral philosophy of ancient India or China. If there is any improvement at all, it is simply in the direction of knowledge of causes and effects. And that is why in all countries the common sense of mankind universally condemns any attempt to interfere with moral ideas. These represent the social experience of man for thousands and thousands of years; and it is not likely that the wisdom of any one individual can ever better them. If bettered at all it can not be through theory. The amelioration must be effected by future experience of a universal kind. We may improve every branch of science, every branch of art, everything else relating to the work of human heads and hands; but we can not improve morals by invention or by hypothesis. Morals are not made, but grow. Yet, as I have said, there is what may be called a new system of ethics. But this new system of ethics means nothing more than a new way of understanding the old system of ethics. By the application of evolutional science to the study of morals, we have been enabled to trace back the whole history of moral ideas to the time of their earliest inception,--to understand the reasons of them, and to explain them without the help of any supernatural theory. And the result, so far from diminishing our respect for the wisdom of our ancestors, has immensely increased that respect. There is no single moral teaching common to different civilizations and different religions of an advanced stage of development which we do not find to be eternally true. Let us try to study this view of the case by the help of a few examples.