Benjamin Kunkel   BUYPaper Promises: Money, Debt and the New World Order by Philip Coggan Allen Lane, 294 pp, £20.00, December 2011, ISBN 978 1 84614 510 0 BUYDebt: The First 5000 Years by David Graeber Melville House, 534 pp, £21.99, July 2011, ISBN 978 1 933633 86 2 You are invited to