There is an awful lot of mischief wrapped up in that statement.
First, it's patently ridiculous for a Christian, whose Savior liberated the world with an act of extreme suffering. Which in pertinent to Sullivan's vow writing, as there is no other way God could have communicated the depth of His love for us. But in a world where suffering is not only avoided but eliminated, we will not know that love.
And if the cultural expectation is that one acts to eliminate, rather than endure, suffering, what does it mean to love somebody "in good times and in bad, in sickness and in health." Whaddya mean? There should be no "bad" -- there should be no "sickness." All good, all health, all the time! And if you're not, then make it so, or you're a genetic defective who never should have been born.
Second, "the ability to suffer" will always be pertinent so long as we aim to do difficult things. We have been living an illusion that we can have our cake without having to bake it, so we do things like think we can invade a country, overthrow their government, but not have to work to maintain it. We bring in illegal immigrants to do work we don't want to pay living wages for, and then are surprised when that starts to have some other bad effects. We think we can solve the global warming by maintaining our current habits but sending some folks a few bucks to plant some trees.
Anything worth doing is going to entail sacrifice. But we are allergic to sacrifice; we expect someone to magically make it go away. I tend to think the world would be a better place if we were either willing to endure the suffering necessary to stabilize Iraq, or realized it would be difficult and didn't invade in the first place. But we're Americans. Suffering is for other people. We can kick some dictator ass and not have to deal with a mess. It'll be taken care of.
Third, eliminating the things we call suffering now will not eliminate suffering, it will just have us define down what we mean by suffering. As Sullivan notes, "And suffering because you have an ugly face and want plastic surgery applies." It's our relative rather than absolute position that defines our happiness. The American standard of living has risen dramatically over the years, but folks sure don't seem much happier. Because I only have a 27" TV without cable, and most of my neighbors have plasma TVs with digital.
Ross Douthat points out that Ezra Klein referred to Down's Syndrome as "medically disastrous." As we eliminate more and more conditions, what is considered unbearable suffering will expand.
I am not morally judging people who have cosmetic surgery, nor am I advocating that those enduring trials forego treatment that would improve their lives for the sake of building up their suffering muscles.
But Postrel's passage, and Sullivan's application of it, go further than that -- we are creating a world where suffering can be eliminated; therefore, suffering is without value. We are imminentizing the secular eschaton.
This is a wicked path; it is the path that has led us to 1 million abortions a year, the war in Iraq, the near genetic cleansing of Down's Syndrome. It has led to an American public allergic to sacrifice, that cannot be marshalled to solve real problems like a broken health care system for poor people, or looming environmental armageddon. Nah, somebody else will take care of that stuff. But man, my fingers are tired from all this typing. I better go take something.
I hasten to add that the impulse behind this notion is not evil, and is in fact good. Alleviating suffering is what the Corporal Works of Mercy are all about, and what Jesuse spent a good amount of His time doing. But like almost anything else, when taken too far, it can become a false god.