Ethical Theory Spring 2019

Making No Difference


Jonathan Glover explores something that we commonly say: “it would be better if no one did this sort of thing, but it would make no difference if I do it.” For instance, you might think that it would be better if no one worked on chemical weapons but also that your doing so wouldn’t make any difference since someone else would take the job in the chemical weapons lab if you turn it down. Or you might say that it wouldn’t make any difference if Jim shot one of the villagers in Williams’s example since the captain will shoot him (and nineteen more) if Jim doesn’t.

Most of us believe that the morality of our actions depends at least in part on their consequences. Utilitarians believe the consequences are all that matters. Whether you’re a utilitarian or not, these sorts of cases pose a puzzle. If it makes no difference whether we do it or not, why do we find these sorts of decisions difficult? And why do we often think it would be immoral to do the thing that we also think makes no difference?

Insignificant differences and the principle of divisibility

Glover draws a distinction between cases in which it seems that your actions would make only an insignificant difference and cases in which it seems that your actions make no difference.

Sometimes when we say “my actions won’t make a significant difference” we are making an error due to what Glover calls a “size illusion.” For instance, we might think “my giving to famine aid won’t make a significant difference to the famine.” That’s usually true: you can give all you have and there will still be famine. But then we slide from this true point to one that is often false: “my giving to famine aid won’t make any significant difference to anyone.” Suppose you only save one person. That’s a significant difference even though it isn’t the same thing as ending the famine.

Sometimes Glover thinks we improperly assimilate cases that involve what he calls absolute thresholds and with those that involve what he calls discrimination thresholds.

Where there is an absolute threshold there is a sharp boundary between one outcome and another. In elections, the sharp boundary is the first vote above fifty percent (or whatever percentage of the vote would represent a tie: thirty-three percent if there are three candidates, and so on). Once that vote has been cast, none of the other votes make a difference.

When there are discrimination thresholds, individual actions contribute to an outcome, but each one is usually too small to measure. Pollution is usually like this. Glover uses an example of using an electric heater when there is limited power, causing a shutdown.

We are often tempted to say that the actions that contribute to reaching a harmful outcome with a discrimination threshold are not harmful themselves. After all, the contribution that each one makes is negligible. If no one notices the effects of what I do, how could it be harmful?

Glover thinks this is wrong. That is the point of his example of the Baked Bean Bandits (Glover 1975, 174–75). This example convinces him of the truth of what he calls the Principle of Divisibility, according to which the harm done by individual actions in these cases should be assessed as a fraction of the “determinable unit” of harm rather than as zero. In the case of the bandits, the harm is definitely determinable: the villagers lose their lunch of 100 beans apiece. Since the 100 bandits steal 1000 beans, each one’s share is 100 beans, or a villager’s lunch. It doesn’t matter that each bandit takes a single bean from 100 plates rather than taking a whole plate for himself.

Emma was not sure that this was enough for Glover’s purposes. In many of the cases we are worried about, the share of harm that an individual’s actions cause does not amount to very much. Everyone in Los Angeles contributes to the polluted air that harms us all, but no one contributes a lot. So even if we assign some harm to each person’s actions, we still haven’t shown that anyone is doing anything wrong.

Zach thought that Glover was trying to do something more modest. He thought that what Glover was trying to do is show that we are often mistaken in thinking that our actions are not harmful at all. As Zach sees it, Glover is just trying to show that we cause harms more often than we think we do.

When I read Glover, I had the same thought that Emma did. But I think Zach has a good point too. He might have had both goals but only hit one.

No Difference

We did not talk about the cases in which people think that their actions make no difference at all. Here are some highlights.

Glover talks about the question “what if everyone did it?” This is sometimes used in response to “it won’t make any difference at all whether I do this.” The idea is that you should not think about the effects of your own actions but the effects of what would happen if everyone acted the way you propose to do. (This is basically what we called “rule utilitarianism” in our discussion of Mill.) Glover does not find this compelling, largely because it is not clear to him how we are supposed to describe the action that we’re imagining everyone will do. For instance, is it “telling a lie,” “telling a lie to prevent a murder,” or “telling a lie to protect my privacy” (Glover 1975, 176)?

Glover’s concept of spirals seems interesting to me. In these cases, your actions could have quite significant effects because the effects, well, spiral (Glover 1975, 179–80). For instance, as political parties lose support, they tend to spiral down. There’s no sense in voting for a party that always loses, for instance. So you might think it’s important to vote to stave off a spiral, even if you don’t think your candidate is going to win.

In my opinion, Glover’s answer to the point about fairness misses the mark. The point about fairness is that it is sometimes unfair not to do your part even when doing your part makes no difference to the outcome. Glover says there is a difference between the person who drops out of pushing a car and the person who doesn’t vote because the first one makes the others work harder while the second doesn’t. He’s assuming that the only thing that matters is whether your action makes a difference to others. But the person who is worried about fairness says that being unfair is bad entirely apart from whether it imposes a burden on others or not.

Key Points

These are the things from today’s class that you should know or have an opinion about.

  1. Size illusions.
  2. The difference between Absolute and Discrimination thresholds.
  3. The Baked Bean Bandits and the Principle of Divisibility.


Glover, Jonathan. 1975. “It Makes No Difference Whether or Not i Do It.” Proceedings of the Aristotelian Society 49: 171–209.