Dr. B R Ambedkar.

10 [Caste prevents Hinduism from being a missionary religion]
	[1:] Whether the Hindu religion was or was not a missionary religion has been a controversial issue. Some hold the view that it was never a missionary religion. Others hold that it was. That the Hindu religion was once a missionary religion must be admitted. It could not have spread over the face of India, if it was not a missionary religion. That today it is not a missionary religion is also a fact which must be accepted. The question therefore is not whether or not the Hindu religion was a missionary religion. The real question is, why did the Hindu religion cease to be a missionary religion?
	[2:] My answer is this: the Hindu religion ceased to be a missionary religion when the Caste System grew up among the Hindus. Caste is inconsistent with conversion. Inculcation of beliefs and dogmas is not the only problem that is involved in conversion. To find a place for the convert in the social life of the community is another, and a much more important, problem that arises in connection with conversion. That problem is where to place the convert, in what caste? It is a problem which must baffle every Hindu wishing to make aliens converts to his religion.
	[3:] Unlike a club, the membership of a caste is not open to all and sundry. The law of Caste confines its membership to persons born in the caste. Castes are autonomous, and there is no authority anywhere to compel a caste to admit a new-comer to its social life. Hindu Society being a collection of castes, and each caste being a closed corporation, there is no place for a convert. Thus it is the caste which has prevented the Hindus from expanding and from absorbing other religious communities. So long as Caste remains, Hindu religion cannot be made a missionary religion, and Shudhi will be both a folly and a futility.