Peter Singer turns 80 this July.

Over five decades, his ideas have influenced how millions of people think about poverty, animals, ethics, and what it means to live a good life. It is a milestone worth celebrating.

Few philosophers have influenced not just academic debate, but how millions of people choose to spend their money, shape their careers, and live their lives.

For more than five decades, he has challenged people to think more carefully about their responsibilities to others – and to act on those conclusions.

What do we owe the poor? He wrote Famine, Affluence and Morality in 1972 and made the case that distance is not a moral excuse, and that if you can prevent something terrible from happening, you probably should. It was a short essay, but people are still talking about it today.

What do we owe animals? Animal Liberation in 1975 challenged readers to extend their moral consideration beyond their own species. It was not an easy argument to sit with. For many people, it changed everything.

What do we owe each other, more broadly? Practical Ethics went where the argument led: on equality, the environment, euthanasia, global poverty. It became one of the most widely read philosophy texts in the world, taught in universities across every continent. The conversation it started has never stopped.

And what can one person actually do? That question became The Life You Can Save in 2009, and then an organisation, co-founded with Charlie Bresler, that has helped direct hundreds of millions of dollars to the world’s most effective charities. A book that became a movement, and a movement that became real change for real people living in extreme poverty.

In 2021, Peter received the US$1 million Berggruen Prize for his contributions to philosophy and culture. True to the principles he has advocated for decades, he donated the entire prize: half to The Life You Can Save and half to organisations working to reduce animal suffering.