Anne McElvoy tours 300 years of British liberalism, starting with rebel thinker John Locke
Barrister Harry Potter on John Stuart Mill's ideas about individual freedom and the state.
Paul Broks asks how we can be sure we are the same person that we were yesterday.
Melvyn Bragg and guests discuss the Social Contract; a key idea in political philosophy.
Rory Sutherland explores how businesses play on our susceptibility to signs of commitment
Criminologist David Wilson looks at Thomas Hobbes and his 'social contract' theory.