The Supreme Court has added a new and mostly positive dimension to the discourse over affirmative action with its ruling permitting sub-classification within Scheduled Castes for reservation in educational institutions and government employment. The 6:1 ruling last week, comprising six opinions with five in favour of sub-classification, overturns a 20-year-old decision by a five-judge Bench (E V Chinnaiah versus State of Andhra Pradesh) that had ruled that Scheduled Castes were homogeneous categories. The latest judgment reverses the 2004 observation by a five-judge Bench that the powers to classify groups as Scheduled Castes lay only with the President