What is nihilism?
It’s the feeling that nothing in the world matters any more than anything else. Nietzsche’s analysis was that people once found meaning in their belief in the Judeo-Christian God, but that in the post-medieval world belief wasn’t sufficient anymore to give people the sense that things really mattered. The basic philosophical issue underlying the book, then, is: how are you supposed to live your life in order to make it possible that things matter again?
Is nihilism an intellectual problem, or an emotional one?
Some people really suffer from the feeling that nothing seems to matter any more than anything else. David Foster Wallace called it a ‘stomach-level sadness.’ I think that’s a pretty good description of it.
I don’t know; isn’t the inability to find enjoyment in anything better described simply as “depression”? Nihilism does seem to me like a primarily intellectual problem, where people know what they love and enjoy but suffer from not being able to justify it. Our Greek and Christian intellectual heritage teaches us that contingent things are worthless, that only timelessness and permanence are worth grasping for, and since nothing but abstract ideas can ever come close to meeting such criteria, anyone who looks for them in the everyday world is going to have to reckon eventually with how to fully embrace things despite their contingency, or else continue to suffer. If I may quote that passage from Steven Ozment again:

The belief that momentary feelings of unity or visions of perfection can survive permanently into everyday life this side of eternity is the ante-room of nihilism and fascism. Such beliefs give rise to ahistorical fantasies, which can never materialize beyond the notion. To the extent that they are relentlessly pursued, they progressively crush the moments of solace that precious moments of grace can in fact convey. Historically such fantasies have spawned generations of cynics, misanthropes and failed revolutionaries who, having glimpsed resolution, cannot forgive the grinding years of imperfect life that still must be lived.

I know when I was young, dumb, and full of existentialism, grappling with the idea of meaning in a godless universe, the feeling of despair I’d get was similar to the vertigo I’d feel when my fear of heights was triggered — even when I knew perfectly well I was safe from any danger of falling, even when I was only looking up at a tall object rather than being high off the ground myself, I couldn’t reconcile that awareness with the optical illusion that had me so terrified. Nihilism, to me, is a similar sort of illusion. Even when your feet are firmly planted on the ground of everyday experience, secure in the meaning to be found there, you’re tormented by an irrational fear of falling anyway.
…I’m adding this section in several hours after having originally posted this, having just seen this article. It’s depressing to see that people like Jared Loughner still read Nietzsche and take away the lesson that they need to violently impose their will on everyone else, but at least decades of scholarship have made it so that an elegant explanation of why he’s so ridiculously wrong to do so presents itself immediately afterward. Thank you, Matt Feeney, I couldn’t agree more:
Nietzsche, oddly, has suffered a similar fate. Because of his assault on religion and rationalist metaphysics, and because of the hints of anarchy in his assorted visions of the future (e.g., “the transvaluation of all values”), he’s taken as the West’s über-nihilist. But he saw himself as the scourge of European nihilism, and possibly also its remedy. Nietzsche saw nihilism as a disease, which grows from, in Alexander Nehamas’ words, “the assumption that if some single standard is not good for everyone and all time, then no standard is good for anyone at any time.” It presents itself as mindless hedonism and flaccid spirit, but also as fanaticism.
So does that make Nietzsche and Jared Lee Loughner philosophical brethren after all, joined in the same fanatical fight against nihilism? In a word, no, and Loughner’s pathological fixation on the meaning of words is the giveaway. One way of looking at Nietzsche’s project is that he set out to teach himself and his readers to love the world in its imperfection and multiplicity, for itself. This is behind his assaults on religion, liberal idealism, and utilitarian systems of social organization. He saw these as different ways of effacing or annihilating the world as it is. It is behind his infamous doctrine of the Eternal Recurrence—in which he embraces the “most abysmal thought,” that the given world, and not the idealizing stories we tell of it, is all there is, and he will affirm this reality even if it recurs eternally.
Jared Loughner’s despair that everything is unreal and words have no meaning amounts to hatred of the world (a mania of moralism and narcissism) for its failure to resemble the words we apply to it. Faced with a choice between real people and some stupid abstraction about words, themselves mere abstractions, Loughner killed the people to defend the abstraction. This, then, really is a kind of nihilism, only not the kind that people think Nietzsche was guilty of. It’s the kind of nihilism that Nietzsche was trying to warn us about, and help us overcome.