The problem with rewiring someone against their will has to do with the second issue I mentioned, not the first one - changing their preferences and their utility function. If you're creating something from scratch, I don't see how that can be an issue without arbitrarily privileging some set of values as 'correct' - if you're creating something from scratch, there are no pre-existing values for the new values to be in conflict with. (The first issue doesn't seem to raise the same problems: I think I would consider it okay, or at least 'questionable' rather than 'clearly bad', to re-wire someone to enjoy doing things that they would be doing anyway to achieve their own goals, if you were sufficiently sure that you actually understood their goals; however, I don't think that humans can be sufficiently sure of other humans' goals for that.)
It's not clear to me how you're mapping this problem to the trolley problem. This is probably because I have some personal stuff going on and am not in very good cognitive shape, but regardless of the cause, if you want to talk about it in those terms I'd appreciate a clearer explanation.
It's not clear to me how you're mapping this problem to the trolley problem.
To me the Trolley problem is largely about how much you're willing to only look at end-states. In the trolley problem you have two scenarios with two options, leaving you with identical end states. Same goes for the House Elf problem, assuming that it is in the wizard's power to create more human-like desires.
The main difference between the cases that I see in the Trolley problems are "to what extent is the person you're killing already in danger?" Being already on a ...
Edit: This is old material. It may be out of date.
I'm talking about the fictional race of House Elves from the Harry Potter universe first written about by J. K. Rowling and then uplifted in a grand act of fan-fiction by Elizer Yudkowsky. Unless severely mistreated they enjoy servitude to their masters (or more accurately the current residents of the homes they are binded to), this is also enforced by magical means since they must follow the letter if not the spirit of their master's direct order.
Overall treating House Elves the way they would like to be treated appears more or less sensible and don't feel like debating this if people don't disagree. Changing agents without their consent or knowledge seems obviously wrong, so turning someone into a servant creatures seem intuitively wrong. I can also understand that many people would mind their descendants being modified in such a fashion, perhaps their dis-utility is enough to offset the utility of their modified descendants. However how true is this of distant descendants that only share passing resemblance? I think a helpful reminder of scale might be our own self domestication.
Assuming one created elf like creatures ex nihilo, not as slightly modified versions of a existing species why would one not want to bring a mind into existence that would value its own existence and benefits you, as long as the act of creation or their existence in itself does not represents huge enough dis-utility? This seems somewhat related to the argument Robin Hanson once made that any creatures that can pay for their own existance and would value their own existance should be created.
I didn't mention this in the many HP fan fiction threads because I want a more general debate on the treatment and creation of such a class of agents.
Edit: Clearly if the species or class contains exceptions there should be ways for them to pursue their differing values.