The word "caste" is derived from the Latin term castus, which signified purity of breed. It was the term used by Vasco da Gama and his fellow-Portuguese adventurers, four centuries ago, as they landed upon the southwestern coast of India and began to study the social and religious condition of the people. The word expressed to them the remarkable bond which held the people together; the subsequent generations of foreigners and English-speaking natives have adopted it as the most appropriate term to express the unique system which prevails all over India. No other people, in the history of the world, have erected a social structure comparable to this of India. For twenty-five centuries it has controlled the life of nearly one-sixth of the human race. Other countries have, or have had, tribal connections, class distinctions, trade unions, religious sects, philanthropic fraternities, social guilds, and various other organizations. But India is the only land where all these are practically welded together into one consistent and mighty whole, which dictates the every detail of human relationship and controls the whole destiny of man for time and eternity. For it should be remembered that India has consistently declined to recognize any distinction between the social and the religious. These are the reverse and the obverse of life; they are brought to the same rules and must yield obedience to the same authority. Religion, to the Hindu, permeates the whole social domain; and social order draws its sanctions from, and is enforced by the penalties of, religion. To marry outside one's caste, to eat food cooked by an outcast, to cross the ocean, to delay unduly the marriage of a daughter,—these, and a thousand other delinquencies which may seem absolutely harmless to a Westerner, are not only regarded as social irregularities, but also as sins whose penalties will harass the soul beyond the grave or burning-ground. Herein does caste reveal its uniqueness, and from this does it pass on to the exercise of its extraordinary tyranny over the people.