What is effective altruism? Philosopher Peter Singer explains.

Back in the 1970s, I wrote an article called "Famine, Affluence, and Morality," which was encouraging us to be altruistic and suggested that if we were affluent, then morality required that we help people to some degree.

So, I used the story of rescuing a drowning child in a shallow pond. I said that if you saw such a child, and you were the only person there to stop the child drowning, but you didn't do it because you were wearing expensive clothes you didn't want to ruin, that would be a horrible thing to do. But if you agree that that's a horrible thing to do when the child is in front of you, then what about when the child isn't in front of you? If it is in a different country, but you can still be very confident that your donation will help them?

The article got widely reprinted in a lot of philosophy anthologies, so it got used in a lot of classrooms. Among those philosophy students were Toby Ord and Will McCaskill. They both read the article, and they were interested in altruism. From very small beginnings, they built up this effective altruism movement, which is now a global movement. It has followers in many, many countries and has been responsible for moving billions of dollars into more effective causes.

Effective altruism suggests that if you are going to be altruistic, then you should try to be as effective as you can with what you're doing.

Our species evolved in circumstances when hard times were unpredictable. There might be droughts and famines, so it was good to increase our order of food if we wanted to survive. Somehow, the genes for doing that remain in us. I'm not against people putting things away in case things get economically tougher, but we can do that with some of our wealth, and we can be quite confident that we'll have enough. We may still have more even beyond what we need to prepare for the future.

Zelkovinsky was an interesting man who had an ability to make money from real estate investments, but he didn't really want the money. He was quite comfortable living with his family in a suburban home near Philadelphia, so he decided that he would give almost all of it away. Zel decided to start looking at the possibility of donating a kidney. He went to a hospital in Philadelphia and told them that he wanted to donate a kidney to a stranger, and they looked at him as if he was a bit crazy.

Eventually, he did persuade them that he would like to donate the kidney to just the next person in line who was compatible. On his estimate, it was only a one in four thousand chance that donating a kidney would lead to his premature death. His kidney saved a life, and he thinks that if he hadn't done that, he would have been valuing his own life at four thousand times that of a stranger.

The term effective altruism actually is something that developed after Zelkovinsky had donated both his money and his kidney. Although he certainly is way out there as an outlier, it does describe what he did.

So whatever your resources are, they might be money, they might be time, they might even be one of your kidneys. But if you are going to donate something like that, make sure it does the most good that it can. Don't waste it.

We all have this attitude to everyday purchases. If your phone has died and you need a new phone, you're going to ask around or go online. If you came home and showed your phone to a friend, and your friend said, "How much did you pay for that?" and you tell them, they say, "What? I could have got that for you for half the price!" You'd feel pretty stupid.

But strangely, that attitude doesn't apply to charities. If you go and give your money to a charity, let's say it's a charity that's raising guide dogs for blind people, and you don't do research before you do that, you don't ask, "Is there some other way I could help blind people that would help more people for less money?" If you did ask that, you would find that giving money for guide dogs is not the best value for your money because it costs a lot of money to raise a guide dog. It costs about forty thousand dollars in the US. It's a good thing to do, but you can restore sight in someone who has...