When we first meet Pierre Anthon, he's standing up on the first day of class and getting all profound on his classmates. Given that he's the resident Philosopher Boy, and this is Denmark, we wouldn't blame you if you pictured him looking all sensitive—he wears hipster glasses, maybe, and skinny jeans with ironic Spongebob boxers. Or something like that.
But in fact, as Agnes tells us, he "was solid and thickset, with a splash of freckles on the nose he'd broken one time in fifth grade when he'd butted some kid from ninth" (3.21). Strong and sensitive? He'd almost be a dream boy, except for the unfortunate fact that he'll compare you to a chimpanzee and suggest that you just go die.
We don't see a lot of evolution of Pierre Anthon's character in Nothing, and that's largely because, in allegorical fiction, characters stand in for ideas. If we look at Pierre Anthon as a mouthpiece for existentialist ideas, it's plain to see that he represents the authentic individual. That means that from the get-go, he knows who he is (nobody, really), what he wants (nothing of course), and where he stands (absolutely nowhere). He knows that nothing is worth doing, so, as he says, he's just sitting in the tree getting used to doing nothing.
Even though Pierre Anthon is a bit negative, his words have a nasty habit of ringing true, and sometimes the truth is hard to hear. Early on, he says to Agnes, "Then how come everyone's making like everything that isn't important is very important, all the while they're so busy pretending what's really important isn't important at all?" (4.20) But the alternative he offers is "… instead they could be sitting here eating plums, watching the world go by and getting used to being a part of nothing" (4.20).
Well, that certainly does sound easier. But what he's missing is the fact that if everyone felt like he did, the world wouldn't go by at all. Human beings have the choice to create something out of nothing, and just because Pierre Anthon sees no point in it doesn't mean he has to be a jerk to the people who disagree. After all, how much more boring would the plum tree be if there were nothing to watch and no classmates with whom to argue?
Nothing is a book about masks: the ones we wear to convince the rest of the world that we're not really feeling what we're feeling or thinking what we're thinking. Pierre Anthon is all about shedding those masks, even though he does put on a balaclava when winter comes.
He's gleeful about calling out others' hypocrisy, like when he breaks down for Agnes the number of hours she'll spend doing meaningless stuff like cooking, cleaning, and studying (apparently he's got a lot of time for math up in that plum tree). He tells her that when all is said and done, she'll have approximately nine total years in which her time isn't given over to mundane responsibility. And, as he puts it, "you want to spend those nine years pretending you've amounted to something in a masquerade that means nothing, when instead you could start enjoying your nine years right away" (4.17).
Fair point, Pierre. But once again, we've got a bone to pick with your argument. But how much nothing can you really enjoy? If you climb up a plum tree and spend the rest of your life there, are you actually enjoying it? Are you actually happy? Pierre Anthon never addresses happiness, nor the fact that some people genuinely enjoy the mundane. He may be Taering's resident Junior Existentialist, but he's ignoring a key component of the philosophy: if meaning is relative based on the experience of the individual, he can't say that what's true for him is true for everyone. In other words, shut up and eat your plums, Pierre.
This flaw in Pierre Anthon's thinking eventually leads to his death. By presuming to speak for his classmates, as he does the day they finally get him to the sawmill, he basically signs his own death warrant. He demands to know why they sold the heap of meaning, telling Sofie, "If that pile of garbage ever meant anything at all, it stopped the day you sold it for money" (23.50). This isn't just a cruel thing to say, it's arguably very, very wrong. After all, plenty of people make a living doing work that means a great deal to them—the surgeon who pays his bills saving lives, for example, or the writer who pens a heartfelt memoir that becomes a bestseller. They're raking in the dough for their efforts and abilities, but it's not like they're meaningless sellouts.
Sure enough, Pierre Anthon's callousness toward his classmates angers them to the point that they beat him to death. What he ignores, in all his talk of nothingness, is the one thing that matters very, very much: treating other human beings with decency, compassion, and kindness, no matter what you think about their ideas. And in the end, it's not their meaningless that Pierre imparts to his classmates—it's their cruelty.