Peter Singer at 80: The price of living your principles

What are you willing to give up in order to do good?A takeaway coffee? A bigger house?  Meat? Ten per cent of your income?Renowned philosopher and ethicist Peter Singer has spent decades exploring that question.You might know his famous "drowning child in a pond" analogy, or his work on animal rights and effective altruism. His ideas have influenced the way we think about our responsibilities to others.As he marks his 80th birthday, we ask Peter Singer what it means to live a life shaped by the question: how can I do the most good?