I suffer from eschatological obsession. That is, I spend lots of time brooding about ends. So the cover of the September Scientific American—which reads simply "the end."—made me all shivery, like when I hear the spooky sitar opening of The Doors' apocalyptic rock poem "The End." (I'm never more Freudian than when I hear Morrison's Oedipal yowl.)

Some issue highlights: Tom Kirkwood's article on why we shouldn't expect the end of death soon (someone send this to Ray Kurzweil); Arpad Vass's description of a corpse's busy afterlife (which reminds me of one of my favorite novels, Jim Crace's Being Dead, Picador 2001); George Musser's riff on whether time can end (which would mean the end of ends—like, grok that, dude!).

The issue inspires me to offer ruminations on some other possible ends:

*Philosophy. Does philosophy have a future? I distinguish between science and philosophy this way: Science takes on questions that can be answered, at least in principle, and philosophy questions that can't. And as science has grown in power, it has grabbed more and more of philosophers' turf. Scientists are mounting an assault on the mind-body problem (see below), and they are probing the roots of morality, an endeavor that New York Times columnist David Brooks equates with "the end of philosophy." But scientists, although they can (try to) tell us where our morality came from and how it works, can't tell us how we should live. There is still a yawning divide between "is" and "ought." Philosophers can stay busy working within the "ought" realm, trying to formulate moral rules. Of course there are no absolute moral rules; moral rules are always provisional, dependent on context, in a way that scientific laws aren't. We don't want masochists living by the Golden Rule, for example, and we all too easily find exceptions to the commandment "Thou Shalt Not Kill." The upside for philosophers is that if you can't ever answer a question, you can argue about it forever. And that's precisely what I expect philosophers to do. The late, great anthropologist Clifford Geertz once said that "progress" in anthropology "is marked less by a perfection of consensus than by a refinement of debate. What gets better is the precision with which we vex each other." That's even truer of philosophy.

*Neuroscience. In the September issue, the neuroscientist Christof Koch declares that brain research may soon solve one of the oldest philosophical puzzles: the mind-body problem. Learning how a brain, mere matter, makes a mind would arguably represent the culmination—the end!—of neuroscience, in the same sense that a quantum-gravity theory would culminate physics. But Koch's declaration is far too optimistic. Neuroscientists may indeed learn enough about how the brain encodes information to help us solve enormous practical problems. Cracking the neural code may help us discover more effective treatments for brain disorders such as schizophrenia, Alzheimer's disease, blindness and paralysis. But I suspect that the neural code will be so hideously complex that it won't give us the sort of intellectual and aesthetic satisfaction—the "Aha!"—we crave. I also disagree with Koch's claim that a theory of consciousness will allow us to determine whether a fetus, a brain-damaged adult, a dog or even the Internet (!) is conscious. Here we are bumping into the problem of solipsism. The basic idea of solipsism is that each of us is trapped in a seamless prison of subjectivity; no one can be absolutely sure that any other human—let alone a sea slug or computer network or right-wing TV pundit like Glenn Beck—is conscious. As I once heard Koch exclaim to David Chalmers, a philosopher who was suggesting that he could solve the solipsism problem, "How do I even know you're conscious?" One caveat: If neuroscientists can design brain chips that allow direct, broadband, wi-fi mind-to-mind communications, all bets are off.

*Mathematics. Not to open a can of worms, but I've always thought of math as less akin to science than to art. Scientists discover, artists invent, and so do mathematicians. Godel's incompleteness theorem established that any moderately complex system of axioms gives rise to questions that cannot be answered with those axioms. By adding to their base of axioms, mathematicians can keep expanding their realm of possible inventions, posing new conjectures and constructing new proofs, forever, just as musicians and poets can keep inventing new forms constructed of sounds and words. The question is, how comprehensible will future mathematical proofs be? Many proofs are now constructed with the help of computers, which can carry out calculations far beyond the capability of mere mortals. Mathematicians like to wax rhapsodic about the elegance, beauty and depth of proofs, but computer proofs often yield truth without insight or understanding. Mathematics is reduced to a mere engineering exercise. So yes, mathematics can, in principle, continue forever. The problem is that no mere human will be able to understand it. "We're not very well adapted for thinking about the space-time continuum or the Riemann hypothesis," the mathematician Ronald Graham once told me. "We're designed for picking berries or avoiding being eaten."

*The World. I grew up in the duck-and-cover era, when global nuclear war between the United States and Russia seemed not only possible but probable. The detonation of tens of thousands of H-bombs would mean, at the very least, the end of civilization, if not all of humanity and even all of life. Remember Carl Sagan's prediction of nuclear winter? Then, incredibly, the Soviet Union dissolved and the Cold War ended with scarcely a shot fired (how many people saw that coming?). Now, I've veered from pessimism to optimism. Sure, we've still got a few problems, but as David Biello notes, humanity is doing better than ever as measured by health, life expectancy and prosperity. Moreover, in spite of the conflicts raging in Iraq, Afghanistan and elsewhere, annual war-related deaths have dropped by two orders of magnitude since the cataclysmic first half of the 20th century. This decline has led scholars such as John Mueller, a political scientist at Ohio State University, to assert that we may be witnessing the beginning of the end of international war. Now there's an end worth celebrating.

*Mystery. The British chemist Peter Atkins is an atheist so hard-core that he makes Richard Dawkins look like the Pope. Atkins has called religion "evil" and belief in God "foolish." He once told me that he believed science would one day solve every question that we can pose, including the biggest one of all: Why is there something rather than nothing? Existence will be so totally solved that there will be no mysteries left. None. Our primordial "Hunh?" of bafflement will turn into a triumphant "Aha!" Our scientific knowledge will be so complete and persuasive that no one will cling to their silly religious beliefs anymore. I find this faith in science's omnipotence almost as weird as Christians' faith in an omnipotent God. My guess is that the more we learn about the universe, the more mysterious it will become. Which means of course that neither science nor religion will ever end.

Image: A desert in Namibia; credit: iStockphoto