(This post is part of a series of Open Questions, in which I describe important questions about which thoughtful people disagree)

People who care about making the world better fall into roughly two camps: those motivated by obligation, and those motivated by opportunity.

Here’s the basic case for obligation: There’s a child drowning in a pool. Do you jump in to save him, even at the cost of ruining your expensive suit?

Most of us would feel obliged to save the hypothetical child. Therefore, the argument goes, we should also feel obliged to save the lives of real children in need — children who are dying of treatable diseases like malaria — even if they’re not right in front of us, and even if it costs us the equivalent of an expensive suit. The “obligation” argument is that we’re morally obliged to help others as long as it isn’t a huge burden on us.

The “opportunity” camp rejects this purported obligation, and instead says: Look, I don’t think I’m morally obliged to help strangers, but I like helping strangers, especially when I find an opportunity to do so that seems especially promising. So I’ll go about my life looking for exciting opportunities to do good, but without feeling obliged.

It’s an empirical question which approach produces the most good, and different people have different intuitions about that question. On the one hand, the opportunity camp points out that the feeling of obligation can be punishing, causing burnout or anxiety that can actually reduce your ability to help others. On the other hand, there are plenty of examples of valuable pro-social behaviors that happen mostly because people feel obliged — do you wait your turn in line, or pick up your litter, or do your fair share of the chores, because you find it exciting? Or because you’d feel guilty if you didn’t?

Meanwhile, the obligation camp sometimes notes that the opportunity camp hasn’t actually explained how they can reject the logic of obligation. There are various answers to this challenge. One of them is the Demandingness objection: that if we accept the logic of obligation then we’re required to give until “it hurts,” that is, until we ourselves are suffering as much as our recipients, or at least until we start impairing our ability to earn money to give away. Many people consider that a reductio ad absurdum of the obligation argument. (Some, however, bite that bullet.)

Another way to counter the obligation argument is to say that the drowning child thought experiment is flawed. There are a lot of ways to attack it, but I’ll pick one: It’s not fair to posit a single drowning child. The more appropriate thought experiment would be to imagine millions of drowning children in pools, since that’s the magnitude of the actual problem facing us. And in that thought experiment, it’s less clear that we’d feel obliged to keep jumping in to rescue the children, until all of our suits (and other possessions) were spent.

Finally, one rejoinder I hear from the obligation camp is that the opportunity folks clearly do accept the existence of moral obligation in some areas. Surely they feel obliged not to murder, cheat, steal, and so on. So why don’t they feel obliged to sacrifice some luxuries to save the lives of suffering people? How do they draw that line?

This doesn’t address the philosophical arguments, but for what it’s worth, I see a trend pointing in favor of the opportunity camp. It seems to me that groups of thoughtful people who are actively trying to help the world tend to move from an “obligation” mindset to an “opportunity” mindset over time.

Relevant reading:

• The names “obligation” vs. “opportunity” come from this post by Luke Muehlhauser, which lays out the basic dichotomy. (In the comments, several leaders of the Effective Altruism movement talk about how common the “opportunity” view is in their circles.)
• Philosopher Peter Singer’s essay in which he poses the “drowning child” thought experiment
• A collection of responses to Singer’s essay and the Demandingness objection to it
• This post from Holden Karnofsky makes the case for “Excited Altruism” (an opportunity perspective)