American philosopher Michael Sandel sparked more soul-searching by asking his mainly Indian audience to debate attitudes towards rape and moral parallels between the sexual and the communal violence India has seen so much of.

BBC: Is Delhi gang rape India's 'Rosa Parks moment'?

Mr Shiller has, for example, a hearty dislike of inequality, and his views are much influenced by John Rawls, an American philosopher, who argued that a just society is one in which increases in inequality are justified only if they benefit the poorest in society.

ECONOMIST: Political economy

Thomas Nagel, a distinguished American philosopher, once remarked that to say now that consciousness is a physical state of the brain is to be in the position of an ancient Greek who proclaims that matter is energy: what he says is true, but there is no understanding of how it can be true, no framework into which to fit the discovery.

ECONOMIST: Philosophy of consciousness

Apart from Sedgefield and Mr Clinton, the other main influence on Mr Blair came from the communitarian ideas of the philosopher John Macmurray and later thinkers, such as the American sociologist, Amitai Etzioni, whom he met in 1995.

ECONOMIST: Bagehot