Castes were the building blocks of Hindu social structure in precolonial India. But with the introduction and development of the new capitalist forces of production these blocks have undergone a fundamental change. From being a hereditary unity of caste and occupations they nave become a unity ofthisvld contradiction plus the new contradiction of caste and class. This basic contradiction in Indian society can be resolved neither by subjectively subtracting the old contradiction from the new one nor by excluding either class or caste from the new set of opposites.