Trolleyology

I've been reading a 2014 book, "Would YOU Kill the Fat Man" by David Edmonds. It explores in some detail the ethical problem often referred to as "the spur" or "the trolley problem", which has given rise to a whole subsection of moral philosophy sometimes jokingly called "trolleyology".

You've probably come across it, or some variant of it: a man sees a trolleybus or train hurtling towards 5 people who are tied to the track, people who will surely be killed if the man does nothing. If, however, he pulls a signal switch, the train or trolley will be diverted to a spur track, but in doing so it will surely kill another person who is tied to the spur track. What should he do?

It or something similar has plagued philosophers for centuries - arguably it dates back to 13th century theologian Saint Thomas Aquinas and his Doctrine of Double Effect - but this modern formulation of the problem is usually credited to the upper class Englishwoman, political activist and Oxford scholar (and friend of novelist Iris Murdoch) Philippa Foot, née Bonsanquet, as recently as 1967. Since then, it has ignited a whole mini-industry of sorts within academia.

This is not just some dusty old academic  philosophical chestnut with no real answer. It is a problem with some very serious real world repercussions. For example, Churchill's sleight of hand around German flying bombs towards the end of the Second World War, imperilling some areas in preference to others; President Truman's decision to kill hundreds of thousands of Japanese civilians with two atomic bombs in an attempt to shorten the war and save even more lives; real life tales of sailors cast hopelessly adrift, who take the life of the weakest in order to save the rest; the decision to kill one conjoined twin in order to save the other; or for a mountaineer to cut loose a colleague so as to ensure that the whole group were not jeopardized. The list goes on. Another aspect of it might be the old argument as to whether torture ever justifiable in the interests of the greater good - to save a person's life? to save ten lives? a thousand? to save the planet? - or is there a "categorical imperative" (to use Immanuel Kant's phrase) that overrides this?

Interestingly, certain formulations of the trolley problem tend to elicit one response, and others the opposite. For example, people often see the spur problem as justifiable, perhaps because it is merely a diversion of an already existing threat, and perhaps because there is a slim possibility that the single victim who is sacrificed for the greater good can also be saved in some miraculous way, subsequent to the initial decision. In the case of the Fat Man version of the problem (the fat man of the book's title), a man has to be actively pushed off a bridge in order to save the five who are tied to the track, and most people find this much more problemmatic. The difference between intending and merely foreseeing a death appears to be key. In another example, that of an unwilling or unsuspecting donor who can save five other patients by the harvesting and transplant of his major organs, most people find this solution absolutely abhorrent, maybe because the death of the donor is such a deliberate, unequivocal and required act.

Other subtle variations of the problem make the decision-making even more complex, difficult and uncomfortable. Judith Jarvis Thompson has spent much time cooking up just such subtle variations, including the unfortunate fat man of the book's title, who needs to be physically pushed off a bridge in order to stop the trolley and save the five porential victims. Frances Kamm has devised other even more subtle, contrived and tortuous variations, some of which divide and baffle even trolleyologists.

So, where does all this leave us? How do we weight up positive duties and negative duties, doing and allowing, foresight and intention, acting and omitting, a concern for emotion and agency and strict numerical utilitarianism?

With the advent of "x-phi" or experimental philosophy, statistics have been gathered on the extent to which ordinary people agree or disagree on the various scenarios of trolleyology. There is a surprising convergence of opinion: for example, between 80% and 90% of people agree that the switch should be pulled in the basic version of the thought experiment, and a similar 80% - 90% agree that the fat man should not be heaved onto the railway line in that version of the story. There are very minor differences between women and men, between the religious and non-religious, between conservatives and liberals, between hospital workers and others, but generally speaking there is a remarkable degree of consistency, regardless of socioeconomic strata, education level, culture and geographical location. Differences can be introduced artificially by changing the order in which a series of scenarios are presented; by changing the person who is making the decision; by introducing personal elements like relatives in danger; by building into the storyline conplicating details like criminals or geniuses or children or dying people on the line, etc, etc. But even then, the deviations from the underlying trends tend to be relatively minor. Does this, then, mean that human morality is innate? Should we, then, be able to teach the agreed "rules" to robots, battle computers, or autonomous cars,

"Would YOU Kill the Fat Man?" is written in a clear and engaging style, and explains complex and confusing concepts in an accessible manner, and with many examples. It is a thought-provoking and mildly challenging read, but not really a difficult or long one. The book veers off towards the end in favour of a consideration of the effect of various drugs and hormones on people's reactions, and of another popular moral experiment known as the Ultimatum Game (interesting enough in itself), but in general it manages to spend almost the whole 200 pages talking about just this single ethical thought experiment. It seems that some moral philosophers have devoted their professional lives to trolley-type dilemmas. Make of that what you will.

So, what would YOU do? Would YOU kill the fat man?