As a recent guest on BBC Radio’s Desert Island Discs, Martin Sheen described why he is a social activist. He said that he never expects to change anyone’s mind through his activism. He does what he does because he has to, it is right. That is not enough for me, and I suspect, not enough for many who work in the charitable sector. There is nothing wrong with being motivated by principle and values alone. But I imagine most of us need to make a difference. If I was not making a difference, I would go somewhere else that pays more!

As an alternative to acting solely out of principle, at New Philanthropy Capital (NPC) we advise our clients about the importance of having a clear, explicit theory of change. Such a theory of change describes how what you do should lead to the impact that you want to have.