That's a central part of philosophy, of ethics. What do I owe to strangers? What do I owe to my family? What is it to live a good life? Those are questions which we face as individuals.

Sometimes we know the best thing to do, but fail to do it. New year's resolutions are often like that. We make resolutions because we know it would be better for us to lose weight, or get fit, or spend more time with our children. The problem is that a resolution is generally easier to break than it is to keep.

When diamonds' role in fuelling violent conflict in Africa gained worldwide attention, the diamond industry established the Kimberley process in order to keep ""blood diamonds"" out of international trade.

I'm not overly alarmist about it, but I do think there are some worrying signs, like the growing accumulation of wealth by a very small proportion of the population, plus elections in the US are much more dominated by money than anywhere else calling itself a democracy.

When it comes to spending, I don't splash out on fancy cars - I never have. I'm not a car man and, in fact, don't even drive. Although I own a vehicle - it only cost £3,000, and I can't even tell you the make - friends are kind enough to drive me around. It doesn't make sense to waste lots of money on cars."

I was poor. When you're poor you work, and when you're rich you expect somebody to hand it to you. So I think being reasonably poor is very good for people.

Well, if you're looking for me to lead a normal representative life, well good luck finding a foreign secretary who'd be like that - totally dependant on the political system and has never earned any money. Then you'll get the politicians you deserve.

I don't want to ever say to somebody, 'You don't have to see it. It's not good.' I'm done with that. I'd love to just do things that I respect. That being said, I do have two children to put through school, so we'll see if I can put my money where my mouth is, but I would love to just work with people I respect.