Thus the new doctrine of the Brahmans removed the old gods and sacrifices, and gave to the old customs of purification a further extension, and in part a new meaning, inasmuch as it developed them into a wide system of expiation; but the change wrought in the sphere of morals was far more radical. The moral law of the Brahmans is distinctly in opposition to the requirements of the old time. War and heroism are no longer the highest aim of life, but patience, obedience, sanctification. As all animals have their origin from Brahman, and to each, at creation, is allotted a special mission, as Brahman is this order of the world, it is man's task to adapt himself obediently to this arrangement of gods, and fulfil the duties laid upon him at birth. At the same time, no one is to disturb another in the fulfilment of his duties. He must injure neither man nor beast; he must spare even the plants and trees. No one must go beyond the limits allotted to him, but lead a quiet and peaceful life within them. Without ceasing, the Çudras must serve the three higher orders; the Vaiçyas must till the field, and tend the herds, and carry on trade, and bestow gifts; the Kshatriyas must protect the people, give alms, and sacrifice; the Brahman must read the Veda, and teach it, offer sacrifice for himself and others, and receive gifts, if poor. It is the duty of each of the lower orders to reverence the higher; the Vaiçyas and Kshatriyas must bow before the Brahmans, and heap gifts upon them.[213] In opposition to the Çudras, who, as we saw, ranged with beasts (p. 142), Brahmans, Kshatriyas, and Vaiçyas were united by community of blood and common superiority of caste. The three upper orders are distinguished from the Çudras as the "Dvijas," the twice-born, in the phrase of the Brahmans. This second birth is performed by investiture with the holy girdle. In old times this ceremony was no doubt the symbol of the reception of boys and youths into the union of the family; at present the girdle is not only the distinguishing sign of the three upper orders, but from the Brahman point of view the pledge of higher illumination. It is put on with solemn consecration, accompanied by the most sacred prayer, and the second, higher birth consists in the mystical operation of this ceremony. But the upper orders were not merely united by origin, by superiority in rank, and this symbol of superiority; the Dvijas alone had access to the worship, the sacrifice, and the Veda.