You can conceivably have a great relationship with your significant other. Can you argue that it it is the best possible relationship?
Yes, if there’s a ceiling on how good a relationship can be at a given point. Compare to eating food—you eat until you’re completely full (and aren’t feeling unwell). You wouldn’t claim that there would only be one best “soulmate meal” that can make you fuller than any other meal, because there is a variety of meals that can make you full and satisfied. The same can be (and, I think, is) true for relationships. There are relationships that are suboptimal, that don’t reach the ceiling, but there are multiple people who do reach the ceiling. If search costs were zero, many people would find several matches between whom they could be genuinely indifferent.
There is also the contrast between the potential quality of a relationship and the actual quality of an existing relationship. Often, your relationship improves as it progresses, so even if you’d meet someone with whom you’d also be hypothetically compatible (maybe even more compatible than with your current partner if you had known both for an equal amount of time), it can still be possible that a relationship with a new person could never catch up in quality compared to the old relationship. This is one of the problems with this scenario. Even if this vethandi would have been more compatible with Stephen had he known her for as long as he had known his wife, it doesn’t mean that their relationship would be better than the relationship with the wife would have been. There is also the effect of resentment to consider. I find it highly likely that at least for some people, replacing their spouses with vethandi would cause a permanent decrease in lifetime happiness.
But for relationships that aren’t as good as they could be—for relationships not at the ceiling, and those that could be surpassed by a vethandi—for people in such relationships, the vethandi replacement would be an improvement. Something on a more minor scale already happens today: people say things like, “My old relationship wasn’t bad, but it ended, and then I met this new guy/girl and they’re much better”.
FWIW, I didn’t think that anything in Friendship is Optimal was creepy.
Yes, if there’s a ceiling on how good a relationship can be at a given point. Compare to eating food—you eat until you’re completely full (and aren’t feeling unwell). You wouldn’t claim that there would only be one best “soulmate meal” that can make you fuller than any other meal, because there is a variety of meals that can make you full and satisfied. The same can be (and, I think, is) true for relationships. There are relationships that are suboptimal, that don’t reach the ceiling, but there are multiple people who do reach the ceiling. If search costs were zero, many people would find several matches between whom they could be genuinely indifferent.
There is also the contrast between the potential quality of a relationship and the actual quality of an existing relationship. Often, your relationship improves as it progresses, so even if you’d meet someone with whom you’d also be hypothetically compatible (maybe even more compatible than with your current partner if you had known both for an equal amount of time), it can still be possible that a relationship with a new person could never catch up in quality compared to the old relationship. This is one of the problems with this scenario. Even if this vethandi would have been more compatible with Stephen had he known her for as long as he had known his wife, it doesn’t mean that their relationship would be better than the relationship with the wife would have been. There is also the effect of resentment to consider. I find it highly likely that at least for some people, replacing their spouses with vethandi would cause a permanent decrease in lifetime happiness.
But for relationships that aren’t as good as they could be—for relationships not at the ceiling, and those that could be surpassed by a vethandi—for people in such relationships, the vethandi replacement would be an improvement. Something on a more minor scale already happens today: people say things like, “My old relationship wasn’t bad, but it ended, and then I met this new guy/girl and they’re much better”.
FWIW, I didn’t think that anything in Friendship is Optimal was creepy.