Following the death of Prince Philip there’s been a lot of talk about duty about how he was a man committed to his duty. However, I’m not sure we are always clear about what we mean by duty.

Duty can be thought of in two ways: positive duty that is the duty to assist; and negative duty which is the duty not to cause harm. It is generally thought that negative duties outweigh positive duties and so are more fundamental.

We also have a question of who we owe a duty to. Do we owe duty to everybody or only close family relatives, neighbours; how far does our obligation extend? The Australian philosopher Peter Singer emphasises positive duty and believes that we owe a duty to everybody in the world, indeed he goes further and calls it a moral obligation. Singer would suggest that we must contribute to the alleviation of world poverty, not because of charity, but because it is a moral imperative.

The American philosopher Thomas Pogge argues that we have a more important negative duty. He believes a significant cause of world poverty is global institutions acting against the interests of the poor.

For example, the way that international finances are organised, trade barriers, membership of key global institutions, but perhaps more significantly the way that rich countries will recognise the leader of another country as being able to borrow money for the country and use its natural resources no matter how that leader came to power. For example, international banks lent Mobutu in Zaire $14 billion, of which $12 billion left the country but leaving the people with a $14 billion debt!

But Pogge goes further and says that we are complicit in this and therefore, both have the negative duty not to harm, and we must do all we can to alleviate world poverty, because the harm was caused by institutions that benefit us.

This is very controversial, and you can certainly argue that our contribution to this, even if we benefit from it, is minimal, and our influence on the institutions such as the IMF is frankly negligible.

But consider, do we owe a duty to others, and if so who are they? Are they only our family or neighbours or those who live in our nation state? Do we have special obligations with separate general obligations and only owe a special duty to our family?

This is a difficult ethical issue at the heart of how we perceive justice. Only recognising a duty to relatives risks us defining justice as dependent on race, gender, or accident of birth. Tricky questions at the heart of how we consider the use of funds. As Charles Darwin said:

If the misery of our poor be caused not by laws of nature, but by our own institutions, great is our sin.