Good-bye Kurt Vonnegut, Jr., whose resemblance to that other great American satirist, Mark Twain, is almost uncanny. And I believe his literary doppelganger would have enjoyed visiting the Vonnegutian universe populated by Kilgore Trout, Wanda June, Eliot Rosewater, Francine Pefko, Paul Proteus, Billy Pilgrim, Howard Campbell, Jr., the planet Tralfamadore, ice nine, granfalloons, foma, Illium, N.Y., and, of course, the lovely Montana Wildhack.

Call him a pessimist, a stoic, or a dark and cranky curmudgeon, Vonnegut, like Twain, supplied what any self-satisfied civilization occasionally needs to keep it honest—a good thwacking from a brilliant satirist.

And thwack he did. Vonnegut straddled literary lines, melding science fiction and social satire like no other writer. In his paratactic writing style he created only slightly alternate universes peopled with antiheroes who stumbled about unstuck in time, or were mired in their own absurdity. His exquisite logical perversions of social, religious and political dogma were filtered through his general pessimism about the human prospect—all while making us laugh, or at least smirk, at our own venality. And when he created his alternate philosophies and religions, he presented to us a distorted carnival mirror with which we could see our own warped reflections.

Vonnegut's science fiction was largely dystopian, and not necessarily positive about the prospects of scientific discovery and technological progress—think of Paul Proteus, the Luddite hero of Player Piano, who leads a rebellion against automation or of the apocalypse wreaked by the invention of ice nine in Cat's Cradle. Yet as a secular humanist he was neither antitechnology nor antiscience, but merely skeptical of its potential in the hands of flawed humanity. And, if he was sometimes critical of what science has wrought (like the insanely sterile logic of the nuclear arms race or destruction of the environment), he was merciless when it came to shooting down the obscurantism and illogic of religious dogma, not to mention our more prosaic consumer excesses and social taboos.

But why did he have such a dark view of the prospects of the evolutionary experiment that is Homo sapiens? I don't think Vonnegut was a disillusioned idealist but always of this mindset. He was a child of the Great Depression and his defining moment was as a POW in Dresden during World War II. He had survived the Allied firebombing there, in a meat locker, while hundreds of thousands of people were incinerated in the city around him. Of course he wrote about this in his most popular novel Slaughterhouse-Five, or The Children's Crusade.

His not so sanguine view of humanity or its prospects, lubricated by his dark humor, would, to little notice, stick a thumb in the eye of the optimism of post-war America. Eventually, however, he found an audience in disillusioned 1960s and 70s college students like myself who were trying to sort out a world that stood on a foundation of technological progress, economic affluence and greater cultural tolerance, yet was contradicted by the threat of nuclear annihilation, poverty abroad and at home, and the festering wounds of race riots and the Vietnam War. Yet I am happy to report that his work was not, as predicted by some critics, a single-generation fad and that his novels are still widely read—and are still conspiring, as he once said of his young audience, to "catch people before they become generals and presidents and so forth and poison their minds with humanity." Hopefully, his poison is also working on the minds of business and social leaders, engineers, doctors and scientists.

After all, any author who can artfully poke fun at our most cherished prejudices, and fertilize the soil of hubris with a healthy dose of uncertainty has me on their side. But look more closely: Vonnegut is more than an alternate universe—dwelling iconoclast. He believed America was a special place, where people could express their thoughts and speak their minds, and with the A.C.L.U. and PEN he fought actively to keep others from infringing on that right.

Though I didn't always agree with his knee-jerk political or blanket antiwar stances, I often find his stoic mantra "so it goes" a remedy against that background despondency that creeps up when I try to make sense of the latest human folly, well-intentioned policy gone awry or random act of natural destruction. And it is always important to remember his idea that humans strive for happiness, but when they achieve it they don't seem to realize it. (Of course, there may be a psychological reason for this. Perhaps he should have read, "Why It Is So Hard to Be Happy" in the February/March 2007 Scientific American Mind.)

I don't think I will ever completely tire of the human race, and one reason is because it occasionally produces authors like Kurt Vonnegut, Jr., to help me keep it all in perspective.