Does Pain Subtract?
Even if I was prepared to accept an experiential standard for judging lives and chunks of lives (which I'm not--see chapter 4 of The Weight of Things), this would have to be the wrong way to go. Looking back on our two weeks in Europe, it's all wrong to say the pain was simply a negative, subtracting from total good.
(1) You get really sore feet if you walk all over Rome all day, but the soreness is a part of a total experience of working hard, seeing everything, being industrious...that I like. I'd get rid of some of that, if I could, but not all of it.
(2) Second, the "pleasure minus pain" equation doesn't capture how we really think about whether pains are "worth it" or not. We endured about an hour of crowds, heat, and our own squabbles as we made our way through the gigantic Vatican museum for the sake of 20 minutes of gazing at the Sistine chapel. (Then went through a second time to look at everything else--this was not quite logical.) It's not at all impossible that the total suffering exceeded the total pleasure yet I judge the pleasure worth the pain. What I'm thinking, apparently, is that the heights of pleasure enjoyed while gazing at Michelangelo are worth enduring all that misery, however the total quantities (duration times intensity, with quality incorporated somehow) compare.
(3) Last but not least, pain can make for lasting memories. In a way, travel is pretty dumb. You go to marvelous places like Rome for a few days or weeks, just to wind up back home long term, finding your environment even less interesting than before (especially if you live in Dallas). The sore feet give your memories (including the pleasurable elements) greater staying power. Example: I stepped on a sea urchin in Hawaii last summer, which was seriously excruciating. I remember that day--what gorgeous skies! what amazing spinner dolphins! what superb underwater corals!--extremely well.
So... pleasure minus pain, bah!