You are standing on the edge of a railroad track. To your left is a runaway trolley heading in your direction. To your right is a fork in the tracks.

Left to its own devices the trolley will veer right at the fork, journey some distance, hit and kill five people working on the tracks. You cannot warn them. At the fork is a switch. If you throw it, you will divert the trolley to the left. This will save the five workers. But, alas, there is one worker on the other track. You cannot warn her. She will be killed by the trolley.

You are a virtuous person. What should you do?

SKELTON

One part of our moral thinking attaches significance to producing socially desirable outcomes or good outcomes for the aggregate. If you are attracted to this thinking, you will likely reason as follows:

Being killed by a trolley is very bad. It will entail the loss of all those things that matter to us: learning, love, friendship, pleasure. The loss of one life is very bad indeed. But if the loss of one life is very bad, then surely (other things being equal) the loss of five lives is much worse; it is five times worse. If you have a very strong reason not to divert the trolley, you have a reason at least five times stronger to divert the trolley.

This reasoning leads a vast majority of people to the conclusion that it is permissible to divert the trolley to save the five workers.

This is a schematic example. It is the stuff of the philosophy classroom. These sorts of examples never happen in real life, and even if they did, we would not recognize them as such. But there are real-life cases that are relevantly similar.

What we learn in the classroom may therefore help us in the real world.

Witness Manitoba Premier Greg Selinger, who earlier this month faced a similar dilemma.

The Assiniboine River flows east into Manitoba from Saskatchewan along an area protected by dikes. This year it was carrying an unprecedented amount of water. If left to its own devices it would likely breach the dikes at some point between Portage La Prairie and Winnipeg, flooding 850 properties across 500 square km of land.

But leaving the river to flow east was not the only option open to Selinger’s government.

The government could cut a hole in one of the dikes – at the Hoop and Holler Bend of the Assiniboine River just east of Portage La Prairie – to produce a controlled flood. That would save the 850 homes. However, this deliberate flooding could cost 150 different homes across an area of about 180 square km.

Selinger and his advisors clearly felt the pull that drives many to think it permissible to choose to divert the trolley in the case above. They must have thought though the loss of 150 houses is very bad and there is a reason not to cut a hole in the dike at the Hoop and Holler Bend, but the loss of 850 properties is five times as bad. Therefore, the reason they had to cut the dike was five times stronger than the reason not to.

On Saturday, May 14, Manitoba officials decided to cut the dike. Though the damage was not nearly as great as predicted, it is still important to ask: Did the government do the right thing?

There is another part of our moral thinking that attaches significance to the dignity and rights of the individual. Here we maintain each individual is owed a certain kind of respect inconsistent with harming them for the purpose of promoting collective social goals or goods. This thinking might form the basis of objections to the government’s proposal. Is this proposal able to overcome these objections?

Did the deliberate flooding involve using people as mere means to an end?

A healthy person would be used as a mere means if, for instance, a surgeon were to cut up and kill him in order to distribute his organs to save five dying patients. It is not clear, however, the government used those living south of the Hoop and Holler Bend as a mere means. The properties were not being used literally to stop the uncontrolled flood. This would happen if, were it possible, the properties were pushed into the river in order to stop the more catastrophic flood from occurring down river. Instead, the flooding is a byproduct of attempting to avert a tragedy.

Did cutting the dike involve deliberately harming people?

In one sense it did. By breaching the dike, the government of Manitoba reasonably foresaw 150 properties could be flooded. One might think if you reasonably foresee something will occur as a result of what you do, then you intend it. However, if intending something is equivalent to reasonably foreseeing that it will occur, then by not cutting the dike the government intended 850 homes be flooded, since they reasonably foresaw this as a consequence of not breaching the dike. Therefore, whatever the government did it would have involved intentionally harming people. In this case, many think it permissible to produce the greater good.

It is very difficult to determine what one intends as opposed to what one merely foresees as an outcome of what one does. Indeed, on some narrow accounts of intention, cutting the dike was intended, but the harm this caused merely foreseen. On this view, it is not clear that cutting the dike involved intentionally harming people. It cannot be impermissible for this reason.

It must also be said it is not clear causing harm deliberately is always wrong. Many think it permissible to redirect the trolley in the case above even though it involves intentionally harming one worker. In this case, one might reason, the benefit is so great it is permissible to intentionally harm.

Was the decision to intentionally flood people unfair? It did not appear to be an arbitrary decision, which is one way in which a decision may be unfair. It seems to have been based on a sober assessment of the scientific facts, among others. But perhaps the worry is not that the decision was arbitrary; rather, perhaps the concern is it was simply unfair to redirect the flood away from the 850 properties without giving those deliberately flooded at least a chance of being spared. It might have been fairer had the government given each of the parties in question an equal chance of being flooded. Since there were two non-overlapping groups, the best thing to do would have been to flip a coin.

This is hard to accept. To treat the two groups as equally worth saving presupposes the extra individuals who live downstream and who would be affected by the flood count for nothing. This appears to accord them no respect.

This is not to suggest the sort of reasoning on which the Manitoba government relied is without difficulty. The decision threatened to affect people’s lives in profound and damaging ways.

This means such reasoning needs to be carried out in an informed, open and accountable fashion. Such reasoning can be corrupted by bias and weakness of will. It must consider the impacts, both broad and narrow, to people, weak and mighty, to property, to ecosystems, to the economy, and beyond. Because information is often unreliable and our collection of it suspect, it is important that we rely on the judgments and deliberations of impartial and well-meaning experts, both scientific and ethical, and deliberations be publicly available. It must be established on the basis of this information that a substantial net benefit could be produced.

This is important. In his address to Manitobans on the night before the controlled flooding took place, Selinger said this was a “one-in-300-year flood.” He seemed to be implying he would not have to make such a decision again in the future, and that the sacrifice on the part of those impacted would be rare (not to mention compensated to some yet unspecified degree). However, the reality of climate change may mean that dilemmas like Selinger’s will occur more frequently.

We all benefit if we have the right reasoning to handle them.

Anthony Skelton is assistant professor in the Department of Philosophy at The University of Western Ontario and faculty member of the Rotman Institute of Philosophy.