The moral foundation of the welfare state is altruism: the doctrine that we have a duty to sacrifice for the needs of others. (See my interviews with Onkar Ghate and Peter Schwartz.) If you want to get a real sense of the meaning of this doctrine and its implications for human life, the best source is Ayn Rand.

But Rand is often accused of caricaturing altruism. Altruism, many people say, isn’t about self-sacrifice but helping others — and this, the claim goes, is compatible with living a happy, prosperous life.

Well, don’t take Rand’s word for it. Check out the works of Peter Singer, who The New Yorker has called “the most influential living philosopher” and who was named by Time as one of the “100 most influential people in the world.”

In his popular book The Life You Can Save, Singer argues that the moral premises everyone accepts make demands that few of us live up to. Here’s his argument (I’m quoting):

• First premise: Suffering and death from lack of food, shelter, and medical care are bad.
• Second premise: If it is in your power to prevent something bad from happening, without sacrificing something nearly as important, it is wrong not to do so.
• Third premise: By donating to aid agencies, you can prevent suffering and death from lack of food, shelter, and medical care, without sacrificing anything nearly as important.

Singer goes on to observe that to most people these are uncontroversial. “Yet if we were to take it seriously, our lives would be changed dramatically.” How so? Well, surely, he says, you could cover the $200 it might take to save a starving child for a year simply by cutting back on, say, clothes “you really didn’t need anyway.” But if you do that, don’t start celebrating, he warns: “there remain more children in need of saving, each one of whom can be saved at a relatively small additional cost.”

The bottom line?

We tend to assume that if people do not harm others, keep their promises, do not lie or cheat, support their children and their elderly parents, and perhaps contribute a little to needier members of their local community [all things that a rationally selfish person might do], they’ve done well. If we have money left over after meeting our needs and those of our dependents, we may spend it as we please. Giving to strangers, especially those beyond one’s community, may be good, but we don’t think of it as something we have to do. But if the basic argument presented above is right, then what many of us consider acceptable behavior must be viewed in a new, more ominous light. When we spend our surplus on concerns or fashionable shoes, on fine dining and good wines, or on holidays in faraway lands, we are doing something wrong.

Read that last sentence again and think about it in the context of your own life. “When we spend our surplus on concerts or fashionable shoes, on fine dining and good wines, or on holidays in faraway lands, we are doing something wrong.” What Singer is saying here is that when we spend money — and, presumably, time — on things that make life enjoyable that is morally wrong. Did you want to build that house you’ve always been dreaming of, buy a new car, travel to Europe, take that cooking class, learn to play the piano, buy that state-of-the-art laptop or a new smart phone, turn that extra room in your house into a library, buy a new surfboard, or just go out to dinner once in a while? The list never ends, and all of it, according to Peter Singer, is wrong.

I submit that if you accept the premise that the needs of others impose a debt on us, then Singer’s argument is unanswerable. This is what it means to take altruism seriously.

And, by the same token, to reject altruism doesn’t mean to harm others, lie, cheat, steal, or refuse to help your friends, family, and neighbors — it means to hold that you have a right to exist for your own sake, including the right to use the money your effort has earned to travel, dress well, eat well, and cap off a romantic evening with a bottle of Bordeaux.