See more of the story

Suppose that a nation, a company or an individual wants to give a lot of money to a university, a nonprofit group or an individual researcher. Suppose that many people think that the potential donor is morally abhorrent, or has done morally abhorrent things.

Is it wrong to take the money?

A lot of real-world cases raise this difficult question.

Loosely analogizing from those cases, here are some scenarios that capture what I have in mind:

• A tobacco company proposes to give money to Princeton University, to support scholarships for poor students.

• A big oil company proposes to give money to a climate researcher, to study the economic effects of climate change.

• China proposes to give money to Johns Hopkins University, to support a new center studying road safety.

• Saudi Arabia proposes to give money to a health economist, to finance research focused on obesity, diabetes and related illnesses.

Reasonable people will disagree about how to evaluate the donors in these cases. For example, some people think that big oil companies are pretty terrible; others have no problem with them. No country is all good or all bad. Let's assume, for discussion, that in all four cases, the donor either is morally abhorrent or at least has done morally abhorrent things.

Consider a simple rule: Just take the money.

The argument would be that if the money would be used for a good cause, it's a lot better to have it than to decline it. If its source is morally abhorrent, the rule still holds. Isn't it better if the money is used to help people, even to save lives?

An initial response would point to the possibility that a donor might impose unacceptable conditions. Suppose that an oil company says that it is eager to make a donation to a climate change researcher — but only if it reserves the right to approve publication of any findings before they become public. If the company means to censor materials that do not fit with its interests, the researcher should refuse the money.

Or suppose that China proposes to give money to a university on one condition: The university agrees not to allow members of its faculty to say anything negative about the Chinese government. That's a deal-breaker.

We should be able to agree that some conditions are unacceptable, even if others are fine (such as an annual reporting requirement, showing how the money has been used) — and even if others can be debated (such as a requirement that any publications be shown to the donor in advance, without any right of approval).

But suppose that in the four scenarios described above, no controversial conditions are imposed. The donor simply says: Take our money and use it however you think best.

Many people would still have moral qualms. But why?

One reason might be psychological. If you accept money from someone, you will feel grateful and perhaps beholden. If an oil company pays for your research, you might feel compromised, even if no conditions are attached to the funding. You might know that you will try to please your donor. You might decline the money for exactly that reason.

In some cases, psychological pressure is unlikely. Even so, many people would argue in favor of refusing the donation by invoking an important but slippery concept: legitimization.

Whenever people take money from a donor, they might be enhancing its reputation. If a tobacco company is willing to fund scholarships, it is probably seeking reputational benefits. An authoritarian government seeking to gain goodwill might embark on a public-relations campaign, including significant donations to worthy causes.

Many people despise the idea of accepting money from donors they consider to be morally abhorrent, on the ground that they are effectively "buying" an increase in legitimacy. They think that the money is dirty.

In one form, their objection is simple revulsion, a feeling of "ick!" But "ick" isn't much of an argument.

In another form, the objection is meant as an effort to establish a social norm, with the expectation that it will have good consequences. The goal is to punish and to deter abhorrent acts.

Refusing to accept money is a way of putting a price on wrongdoing. It is an effort to prevent wrongdoers from getting the reputational benefit that they seek. It is a little like the movement to get universities to divest South African assets during the apartheid era — or the current movement to get them to divest from oil companies.

In some circumstances, the objection is convincing. In others, it really isn't. There's usually some weighing to be done.

How abhorrent is the donor? How, and by how much, would the donor benefit from the donation? Might it be beneficial to engage with the donor? Would the money be put to important uses? Would it improve public health? Would it save lives? (If so, refusing to accept the money might be a moral wrong.)

Clear principles might eventually emerge from asking questions of this kind. For now, let's keep it simple. If a donor imposes no strings of any kind, and if the donation could be used to help real people in really significant ways, here's a rebuttable presumption: Take the money.

Cass R. Sunstein is a Bloomberg Opinion columnist. He is the author of "The Cost-Benefit Revolution" and a co-author of "Nudge: Improving Decisions About Health, Wealth and Happiness."