"You are out for a walk one day and see a runaway train hurtling
down the tracks towards five workers. The driver is uncon-
scious, possibly as the result of a heart attack. If nothing is done,
all will die. The train will squash them. It’s travelling much too
fast for them to get out of the way. There is, however, one hope.
There is a fork in the tracks just before the five men, and on the
other line there is only one worker. You are close enough to
the points to flick the switch and make the train veer away
from the five and kill the single worker. Is killing this innocent
man the right thing to do? In terms of numbers it clearly is: you
save five people by killing just one. That must maximize happi-
ness. To most people this seems the right thing to do. In real life
it would be very difficult to flick that switch and watch someone
die as a result, but it would be even worse to hold back and
watch five times as many people die."