One of the chapters in his book "Saturn's Children" is devoted to an explanation of his support for the legalisation of all drugs. This chapter was removed when the paperback edition was published to prevent embarrassment to the Party leadership. The omitted chapter was available on Duncan's personal website; however, as of 2011 it no longer appears. He believes in minimising the size of government, and in "Saturn’s Children" advocated limiting government responsibility to essential services such as defence, policing and health. In 2002, he was described by the BBC as a "staunch" Eurosceptic. However, he declared for the 'Remain' camp in the run-up to the UK's referendum on EU membership.