The decline of Indian Buddhism was centrally due to the fact that it never offered the Indian laity a complete religion. Early Buddhism knew no ceremonies for birth and death, marriage, illness, and other critical turns of private life... Only for the community of monks did Buddhism provide a complete and well-defined way of life.... But Brahmins were needed for all the ordinary crises in life, ready with their rites and sacred formulas to ward off danger or minimize the damage. This elemental fact assured the survival of Brahminism in India.

The Rise of the West: A History of the Human Community (1963)