THE ORIGIN OF CASTES.--The conflict of races in Northern India gave rise to what is known as the system of castes; that is, society became divided into a number of rigid hereditary classes. There arose gradually four chief castes: (1) Brahmans, or priests; (2) warriors; (3) agriculturists and traders; and (4) serfs, or Sudras. The Brahmans were those of pure Aryan blood, while the Sudras were the despised and oppressed non-Aryan aborigines. The two middle classes, the warriors and the cultivators of the soil, were of mixed Aryan and non-Aryan blood. Below these several castes were the Pariahs, or outcasts, the most degraded of the degraded natives. [Footnote: At a later period, the Brahmans, in order to perpetuate their own ascendancy and to secure increased reverence for their order, incorporated among the sacred hymns an account of creation which gave a sort of divine sanction to the system of castes by representing the different classes of society to have had different origins. The Brahmans, the sacred books are made to say, came forth from the mouth of Brahma, the soldier from his arms, the farmer from his thighs, and the Sudra from his feet. ] The system of castes, modified however by various influences, particularly by the later system of Buddhism (see p. 11), has characterized Hindu society from the time the system originated down to the present, and is one of the most important facts of Indian history. THE VEDAS.--The most important of the sacred books of the Hindus are called the Vedas. They are written in the Sanscrit language, which is believed to be the oldest form of Aryan speech. The Rig-Veda, the most ancient of the books, is made up of hymns which were composed chiefly during the long period, perhaps a thousand years or more, while the Aryans were slowly working their way from the mountains on the northwest of India across the peninsula to the Ganges. These hymns are filled with memories of the long conflict of the fair-faced Aryans with the dark-faced aborigines. The Himalayas, through whose gloomy passes the early emigrants journeyed, must have deeply impressed the wanderers, for the poets often refer to the great dark mountains. BRAHMANISM.--The religion of the Indian Aryans is known as Brahmanism. This system gradually developed from the same germs as those out of which grew the Greek and Roman religions. It was at first a pure nature-worship, that is, the worship of the most striking phenomena of the physical world as intelligent and moral beings. The chief god was Dyaus-Pitar, the Heaven-Father. As this system characterized the early period when the oldest Vedic hymns were composed, it is known as the Vedic religion.