 This theory is now widely believed to be baseless and false.Derryl MacLein, a professor of social history and Islamic studies, states that historical evidence does not support this theory, whatever evidence is available suggests that Muslim institutions in north-west India legitimised and continued any inequalities that existed, and that neither Buddhists nor "lower caste" Hindus converted to Islam because they viewed Islam to lack a caste system.Conversions to Islam were rare, states MacLein, and conversions attested by historical evidence confirms that the few who did convert were Brahmin Hindus (theoretically, the upper caste).