Love and Intrapersonal Utility Comparison
I come down firmly on Jonathan's side of the IUC debate, but (in addition to my comments on Brian's post), I have a different example to give.
Here is my theory: I believe that married people (or those in long-term relationships) are more likely to believe in the possibility of intrapersonal utility comparison (IUC). For what is love if not the embracing of your spouse's utility function, the integration of their happiness into your own? Husband and wife are no longer selfish individual maximizers, but instead maximizing some weighted combination of their interests.
And after some practice ("But I thought you would like a lime green couch"), most couples manage to do pretty darn well at it. It should be obvious that to do this, to effectively maximize mutual utility, IUC's are indispensable. A good spouse does them constantly, in fact, as part of every decision that affects both parties.
Now, you can argue solipsistically that no one can every truly *know* anyone else's feelings, and I grant that there is a great deal of truth to it. It is also true that the accuracy of any measurement of position and momentum is restricted to be at most:
But y'know, with this limited degree of accuracy granted to us by Heisenberg, we are able to measure position and momentum well enough to launch satellites, send men to the moon, and fire missiles thousands of miles with great accuracy. All this despite the fact that we can never really know exactly where those satellites, spaceships, and missiles are.
A measurement can have some error, and still be damn useful. And while I hate to make such an ad hominem argument, I can't help but wonder how many of the single men arguing against IUC will still believe it after a few years of marriage.
Cardinal Schmardinal, Ordinal Schmordinal
IUCs and the Law of Large Numbers
No Soul Suggests IUCs
What color does a submarine weigh? (True or False?)
Exploding IUCs on the roadside
Interpersonal Utility Comparisons
Pareto Efficiency and Justice
Can the Paradox of the Non-Comparability of Interpersonal Utility be Resolved?