In the prairies and the woods our earliest ancestors saw myriads of animals, all living in clans and tribes. Countless herds of red deer, fallow deer, reindeer, gazelles, and antelopes, thousands of droves of buffaloes and legions of wild horses, wild donkeys, quaggas, zebras, and so on, were moving over the boundless plains, peacefully grazing side by side. Even the dreary plateaus had their herds of llamas and wild camels. And when man approached these animals, he soon realised how closely connected all these beings were in their respective droves or herds. Even when they seemed fully absorbed in grazing, and apparently took no notice of the others, they closely watched each other's movements, always ready to join in some common action. Man saw that all the deer tribe, whether they graze or merely gambol, always kept sentries, which never release their watchfulness and never are late to signal the approach of a beast of prey; he knew how, in case of a sudden attack, the males and the females would encircle their young ones and face the enemy, exposing their lives for the safety of the feeble ones; and how, even with such timid creatures as the antelopes, or the fallow deer, the old males would often sacrifice themselves in order to cover the retreat of the herd. Man knew all that, which we ignore or easily forget, and he repeated it in his tales, embellishing the acts of courage and self-sacrifice with his primitive poetry, or mimicking them in his religious tribal dances.... Social life--that is, _we_, not _I_--is, in the eyes of primitive man, the normal form of life. _It is life itself_. Therefore "we" must have been the normal form of thinking for primitive man: a "category" of his understanding, as Kant might have said. And not even "we," which is still too personal, because it represents a multiplication of the "_I's_," but rather such expression as "the men of the beaver tribe," "the kangaroo men," or "the turtles." This was the primitive form of thinking, which nature impressed upon the mind of man. Here, in that identification, or, we might even say, in this absorption of the "I" by the tribe, lies the root of all ethical thought. The self-asserting "individual" came much later on. Even now, with the lower savages, the "individual" hardly exists at all. It is the tribe, with its hard-and-fast rules, superstitions, taboos, habits, and interests, which is always present in the mind of the child of nature. And in that constant, ever-present identification of the unit with the whole lies the substratum of all ethics, the germ out of which all the subsequent conceptions of justice, and the still higher conceptions of morality, grew up in the course of evolution.