Those figures are static or in some countries worsening: given the demography (Romani families are usually large), improving schooling is a matter of urgent European self-interest as well as of principle.

ECONOMIST: Europe's Romanies

In this electoral season, frenzied horse-trading has created some unholy alliances, and what many see as a wholesale sacrifice of principle for maslah (self-interest).

ECONOMIST: Lebanon

And yes, for all the talk of principle, many Tories might just be voting for electoral self-interest rather than an enthusiasm for improving democracy.

BBC: Boundaries: a running sore?

In the 200 years since Kant, a key principle of ethics has been that motivation must be free of self-interest, and intrinsically good, if it is to be recommended as a guide for behaviour.

ECONOMIST: Company goods

No principle or vision is sacrosanct in Washington except its own security and self-interest.

CENTERFORSECURITYPOLICY: Answering a critic of 'Shariah: The Threat to America'