The real world never behaves like the world of a thought experiment. In science, thought experiments are proposed. But no conclusions can be drawn until you actually do the experiment in the real world. The real world contains variables no thought experiment can ever account for. And no one is ever gonna try this one for real.
The thought experiment in question is pretty cruel (read the linked piece, see for yourself), and that made me think about how thought experiments are often used like this. Not as a way to spur thought, but instead as a way to attack someone, or to make them uncomfortable because it's fun to watch people squirm. (If you think it's fun to watch people squirm, kiss me goodbye.)
I am not reacting out of surprise, but dismay. I don't think there's anything in this world that can't be weaponized and used as a way to drive a wedge between people — although that's not a sign we should do nothing in life but hide under our beds and take shallow breaths.
The best thought experiments are what Paul Krugman once described as "toy models" for thinking about the world. They don't have to take into account every possible aspect of a situation, just the largest and most significant. Modeling the situation for the sake of forensic accuracy is not the point; shrinking the problem to a small enough clutch of parameters to get our minds around it is.
The people who use thought experiments as weapons are not interested in any of this. Their job is to get a rise out of their self-described opponent or nemesis, by any means available. One example I came across went like this: If you had a ten-year-old kid who was dying of cancer and had one wish to be fulfilled, would you fulfill that wish even if it was [insert egregiously amoral and utterly unrealistic example of wish-fulfillment by any ten-year-old ever]?
One of the convenient things about abusing a thought experiment in this vein is it gives the attack a veneer of intellectual legitimacy and respectability. I'm just asking you a question. Surely you can't be all that upset by a mere question! If you're not familiar with the way discourse can be weaponized, you won't even realize you're being goaded; you just know that your blood pressure's rising and you're finding it harder and harder to say something that isn't somehow going to be used against you. No-win arguments like this are how everyone from Holocaust deniers to young-earth creationists turn public debates into public theater, and a good reason why any such public debate is a dead end.
Lawyers are wont to say that extreme cases make bad policy, and no-win thought experiments are no different. In the right hands — that is, in the hands of people who are not simply interested in making some purported opposition squirm — they can be useful as way to get people to lay out their reasoning about moral quandaries. But in public settings they're almost never used this way.
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