Thought
experiments are used in philosophy and ethics, philosophy, and even science as
a way of clarifying and testing concepts and theories. For example, ethicists
can use thought experiments to present a hypothetical dilemma, and examine the
most “intuitive” response, drawing out implications for ethical issues in the
real-world.
I
thought (no pun intended) it might be fun to blog some well-known thought
experiments, hopefully as part of an occasional series. As well as examining
your own ethical reasoning processes, thought experiments are also useful as a
revision exercise: you use them to test out and evaluate the ethical theories
you are studying in your A level.
A
runaway trolley car is hurtling down a track. In its path are five people who
will definitely be killed unless you, a bystander, flip a switch which will
divert it on to another track, where it will kill one person. Should you flip
the switch?
So have a think – what would you do?
Our second thought experiment develops this scenario a little. It’s
called The Fat
Man and the Trolley Car.
The
runaway trolley car is hurtling down a track where it will kill five people.
You are standing on a bridge above the track and, aware of the imminent
disaster, you decide to jump on the track to block the trolley car. Although
you will die, the five people will be saved.
Just
before your leap, you realise that you are too light to stop the trolley. Next
to you, a fat man is standing on the very edge of the bridge. He would
certainly block the trolley, although he would undoubtedly die from the impact.
A small nudge and he would fall right onto the track below. No one would ever
know. Should you push him?
Again - have a think – what would you do?
Were your answers to the two scenarios different? If so, you’re
not alone. In a survey conducted
by the BBC, roughly 75% of respondents said they would
flip the switch in the first scenario, versus 25% who said they would not.
However, in the second scenario, these proportions were pretty much reversed: 27%
said that they would push the fat man, while 73% said they would not.
Given that the moral dilemma is, at least on one level, exactly
the same (either one person dies or 5 people die), comparing these two thought
experiments raises some interesting questions about how we make moral choices
and how (in)consistent our ethical decision-making processes are.
Questions to consider:
1) Most people understand that the issue in both thought
experiments is the same (1 person dies or 5 people die), so why do you think
that the response to the two scenarios varies so much?
2) Think about two of the ethical theories you’ve studied. If you
apply the principles of these theories, which is the “correct” ethical response
in each scenario? What might that tell you about your ethical theories and how
useful they are in making ethical decisions?
3) When I’ve tried these thought experiments with GCSE and A level
students, I find it’s very common for students to try to justify their decision
by allocating some sort of blame which is not an explicit feature of the
scenario (e.g. “it’s the people’s fault for being on the track”, “it’s the
man’s fault for being fat”, “if the man was on the edge of the bridge, he was
probably suicidal anyway”). What might these justifications tell us about the
way we make ethical decisions?
4) Do the issues raised by the two thought experiments have any
implications for any real-life ethical issues?

