In tonight's fourth semi-final are David Steele (local government accountant) on the life and career of President Truman;
Paul Webbewood (civil servant) on the life and career of Oliver Cromwell , 1599-1658;
Dave Ross (welfare rights worker) on European political history, 1870-1945;
Bernard Howell (civil servant) on the novels of William Golding.
With Magnus Magnusson at the University of Essex, Colchester. Director Andrea Conway Producer Peter Massey