“The morality which emerges from the observation of the whole animal kingdom may be summed up in the words: "Do to others what you would have them do to you in the same circumstances. And it adds: "Take note that this is merely a piece of advice; but this advice is the fruit of the long experience of animals in society. And among the great mass of social animals, man included, it has become habitual to act on this principle. Indeed without this no society could exist, no race could have vanquished the natural obstacles against which it must struggle.”