"PHILOSOPHICALLY SPEAKING...":

Does our sense of probability, of our luckiness, influence our moral intuition? This article, from Philosophy Now (UK), uses variations on the trolley problem to make a compelling case that it does.

"The thought experiment known as the Trolley Problem was introduced to ethics by the late Philippa Foot. I first heard of it when my lecturer asked our Actuarial Science honours class about it. The thought experiment goes as follows: You see that a runaway trolley car (or tram, if you are British) is about to kill five people walking along a track. But you are standing by the lever that switches the points, and if you pull it the trolley will divert onto another track where only one person is stuck, whom the trolley will then kill instead. Time is running out. Do you pull the lever? ... I decided to test this on a new group of friends. Once again I presented them with the classic trolley thought experiment; and once again they all wanted to pull the lever to save the five at the expense of the one. This time, however, I then took a different approach to show them that their utilitarianism is on shaky grounds: I provided them with ‘another way’. What if there actually is a brake on the trolley – but it only has a 50% chance of stopping the trolley before it kills the one or the five? And unfortunately, there isn’t enough time to pull both the brake and the lever. What would you do? Would you pull the brake, or would you pull the lever? Most of them pull the brake. They say they do this because there is a chance of the best case scenario where no one dies. I challenge them, pointing out that 50% of five is 2.5: therefore there is an expected 2.5 people dying by pulling the brake, and only an expected one person dying by pulling the lever – so based on utilitarian principles, you should pull the lever and not the brake. They still insist on choosing to pull the brake.

"I think what we’re seeing here is that in a deterministic scenario people tend to a utilitarian position, yet as soon as we add uncertainty, people’s ethical reasoning changes. Why? Is it because uncertainty introduces hope and we’re naturally optimistic? Or is it because the very uncertainty removes a degree of responsibility: 'It’s the brake’s fault. Those people were unlucky. I’m not to blame'? ...

"If the brake only has a 10% chance of saving the five lives, would you still pull it? What if the chance of the brake working is unknown? In life we usually don’t know the probabilities associated with our actions; we can only guess them...."
philosophynow.org/issues/132/Ethics_and_Uncertainty