"A trolley is hurtling down a track towards five people. You are on a bridge under which it will pass, and you can stop it by putting something very heavy in front of it. As it happens, there is a very fat man next to you – your only way to stop the trolley is to push him over the bridge and onto the track, killing him to save five. Should you proceed?"
- Judith Jarvis Thomson’s Fat Man version of the Trolley Problem
Harming others directly through hands-on action is harder on our psyches than causing harm indirectly, either through inaction or action at a remove (e.g., pulling a switch, pressing a button). It’s unsurprising then that many subjects in studies on the Fat Man Trolley Problem have disapproved of pushing the Fat Man. The gut resists and very often the gut calls the shots. End result: five imaginary people die instead of one.
Even when the right thing to do is obvious, we hesitate if the right thing to do requires directly inflicting harm on innocent parties. Even when we know better. Even when the choice is clear and there’s no doubt about possible outcomes.
Of course, reality is much messier than thought experiments. For one thing, the consequences of our actions or inaction are harder to gauge and rarely come with 100% certainty. This lack of absolute certainty makes it much easier to rationalize our decisions and simply go with the gut. The real-world result is more suffering, less angst.