These facts, and a thousand other pitiable phenomena of the same kind in human society, bear witness to the egoistic and rapacious nature of man, which proves how little the social instinct is developed in his brain. Human society is founded much more on custom and tradition, imposed by the force of circumstances, than on nature. Human infants resemble kittens at first much more than young social beings. In primitive times, when the earth appeared large to man, the rights of groups were limited to small communities which looked upon other men, the same as animals and plants, as legitimate prey. Cannibalism and even the chase show clearly that man began by becoming more rapacious and more carnivorous than his pithecanthropoid ancestor, and his cousin the ape of the present day. It is only later, after the progressive enlargement of stronger communities at the expense of weaker; still later, when man commenced to comprehend the sufferings for the community which result from the autocracy and passion for unlimited pleasure of a few persons; finally, when he discovered the narrow limits of the earth, that notions of humanity and humanitarianism, that is to say the sentiment of human solidarity, were able to develop in the general conscience. It was, however, one of the ancients who said "I am a man and nothing human can be strange to me." But in his time, as in that of Jesus Christ, civilization was already far advanced and influenced by the wide humanitarian ideas, more ancient still, of the Assyrians and the Buddhists. Every one who reflects will understand that the relativity of the rights of groups in man and that of the duties which correspond to them, must in time expand and be applied, little by little, to all the human inhabitants of the earth. What is more difficult is the definition of what should be understood under the term of humanity, capable of being socialized and cultivated. No doubt, the gap which exists between the lowest living human race and the highest ape is considerable and without direct transition. However, we gradually begin to recognize, on the one hand, that we have certain duties toward animals, at least toward those which serve us, and, on the other hand, we know that certain of the lower human races, such as the pigmies, the Veddas and even the Negroes, are inaccessible to a higher civilization, and especially incapable by themselves of maintaining what a number of their individuals learn by training when they live among us. We shall, therefore, have to choose finally between the gradual extinction of these races or that of our own.