Among the numerous and varied forms of religion which, in the course of the past ten thousand years and more, have been evolved from the crudest prehistoric beginnings, the foremost rank undoubtedly belongs to those two forms which still continue to be the most widely accepted among civilised races--the older Buddhism and the younger Christianity. The two have very many features in common, alike in their mythology and in their ethics; indeed, a considerable part of Christianity has come directly from Indian Buddhism, just as another part is drawn from the Mosaic and Platonic systems. But, looked at from the point of view of our present stage of culture, the ethic of Christianity appears to us much more perfect and pure than that of any other religion. We must, it is true, hasten to add that it is exactly the weightiest and noblest principles of Christian ethic--brotherly love, fidelity to duty, love of truth, obedience to law--that are by no means peculiar to the Christian faith as such, but are of much older origin. Comparative psychology proves that these ethical principles were more or less recognised and practised by much older civilised races thousands of years before Christ. Love remains the supreme moral law of rational religion, the love, that is to say, that holds the balance between egoism and altruism, between self-love and love of others. "Do to others as you would they should do to you." This natural and highest command had been taught and followed thousands of years before Christ said: "Thou shalt love thy neighbour as thyself." In the human family this maxim has always been accepted as self-evident; as ethical instinct it was an inheritance derived from our animal ancestors. It had already found a place among the herds of Apes and other social Mammals; in a similar manner, but with a wider scope, it was already present in the most primitive communities and among the hordes of the least advanced savages. Brotherly love--mutual support, succour, protection, and the like---had already made its appearance among gregarious animals as a social duty; for without it the continued existence of such societies is impossible. Although at a later period, in the case of man, these moral foundations of society came to be much more highly developed, their oldest prehistoric source, as Darwin has shown, is to be sought in the social instincts of animals. Among the higher Vertebrates (dogs, horses, elephants, etc.), as among the higher Articulates (ants, bees, termites, etc.) also, the development of social relations and duties is the indispensable condition of their living together in orderly societies. Such societies have for man also been the most important instrument of intellectual and moral progress.