ShowbizDebate: Open Your MindRichard Goodwin|Evening Standard11 April 2012The British Empire Was a Force for Good6pm, The Royal Geographical Society, 1 Kensington Gore, SW7. £20. Tube: South KensingtonYasmin Alibhai-Brown and Professor Niall Ferguson are amongst the speakers at this latest Intelligence Squared debate, focusing on our colonial legacy. 020 7494 3345MORE ABOUTGeographyKensington And ChelseaWest London