A very sad announcement from AP:
"Ronald Dworkin has died. He was 81.
His family said Dworkin died of leukemia in London early Thursday.
Dworkin was a professor of law at New York University and emeritus professor at University College London.
He was one of the best known and most quoted legal scholars in the United States and also an expert on British law.
He articulated the moral idea that the state should act on principle so each member of the community is treated as an equal.
A frequent contributor to the New York Review of Books, Dworkin's books included "A Matter of Principle," ''Law's Empire," and "Justice for Hedgehogs."
He is survived by his wife Irene Brendel Dworkin, his children Anthony and Jennifer Dworkin and two grandchildren."