The Investigations offers a conception of language that is diametrically opposed that of the picture theory of the Tractatus. In Wittgenstein's early work, language is something sublime, logical, abstract—something with a defining structure or essence that, if you think hard enough, you can puzzle out in your head. In the Investigations, by contrast, language is seen as a messy human phenomenon, part of social reality—a rich variety of everyday practices that you figure out the way a child does, by publicly engaging in them, getting the hang of the unspoken rules by which communities use them. The shift in imagery is from language as a picture to language as a tool. This is the point of the Wittgensteinian mantra "meaning as use": If you want to understand the meaning of a word or phrase or gesture, you don't try to figure out what it represents; you try to figure out how to use it in real life. Wittgenstein called the rule-governed social practices that determine meaning "language games."
As Wallace was delighted to discover when he immersed himself in the Investigations later in college, the implications of this view for solipsism are potentially devastating. Given Wittgenstein's conception of language as a public phenomenon, whereby words get their meaning only by virtue of their shared use, what are we to make of the notion of a strictly private language, the voice of a solipsistic "I" who is speaking only to himself, in his own unique tongue, reporting private sensations and entertaining private thoughts in an otherwise barren world—the voice of a person living entirely in his own head? Wittgenstein's answer was that this idea, though seemingly viable, at least as a thought experiment, is in fact incoherent. The meaning of words is their use; the use of words is a matter of following rules; and following rules is entirely a social affair. There cannot be thought apart from the use of language—and language can operate only within a set of social practices. Thus there is no private thought without a corresponding public reality. "An 'inner process,' " as Wittgenstein put it, "stands in need of outward criteria." To phrase it in Cartesian terms: I think, therefore I am part of a community of others.
Wallace told McCaffery that Philosophical Investigations was "the single most beautiful argument against solipsism that's ever been made." Though the anti-private-language argument has been extraordinarily controversial, Wallace heralded it as though it were an indisputable mathematical proof. "The point here," he wrote in "Authority and American Usage," while giving a summary of Wittgenstein's argument, "is that the idea of a private language, like private colors and most of the other solipsistic conceits with which this reviewer has at various times been afflicted, is both deluded and demonstrably false." Solipsism was dead. Loneliness—at least that image of loneliness—was an illusion.
The defeat of solipsism was half of what Wallace sought to capture in Broom. But while Wittgenstein may have "solved" solipsism for Wallace, there was a catch—a final entangling conundrum with its own frightening implications—which Wallace also wanted to convey. On its face, the account of language in the Investigations seems pleasantly, reassuringly everyday: language is an ordinary, familiar, social, custom-bound human activity. But in other respects the account is quite extreme. Because all language and thought take place inside some language game or other, there is no transcendent, non-language-game standpoint from which you can step back, as it were, and see if any language game is better than any other—if one of them, for instance, does a better job of mirroring reality than another. Indeed, the question of whether any language game accurately represents reality can be asked only within some other language game, which operates according to its own set of nonevaluable conventions. In his early work Wittgenstein was in the business of stepping back from language, appraising its relation with reality, and pronouncing which uses connected us with something real and which did not; the Investigations is in another business altogether, describing without judging, merely "assembling reminders for a purpose," in Wittgenstein's phrase.
In Wallace's view, Wittgenstein had left us, again, without the possibility of contact with the outside world. As he told McCaffery, the Investigations "eliminated solipsism but not the horror." The only difference between this new predicament and that of the Tractatus was that rather than being trapped alone in our private thoughts, we were trapped together, with other people, in the institution of language. This was warmer than solipsism, but, as another form of being sealed-off from reality, it was cold comfort. Explaining this disheartening realization, Wallace said that "unfortunately we're still stuck with the idea that there's this world of referents out there that we can never really join or know because we're stuck in here, in language, even if we're at least all in here together."
In The Broom of the System, these two dueling emotional reactions—the fear of being trapped in language and the relief that at least we're all trapped in it together—are given playful expression. Lenore suffers from a fear, as she explains to her psychiatrist, that Gramma Beadsman is right that "there's no such thing" as "extra-linguistic anything." (Wallace's metafictional joke is that, for Lenore, as a character in a novel, there really isn't any reality other than language.) Lenore's boyfriend, a magazine editor named Rick Vigorous, soothes her throughout the book by compulsively telling her stories. Each of his stories is a not-so-thinly veiled allegory of the problems in their relationship, so that, even within the confines of the novel, Lenore and Rick become characters joined together in a reality constituted entirely by language. In the novel's climactic scene, a televangelist-charlatan named Reverend Sykes provides another image of this same double bind: escaping loneliness together in a language game, but sealed off from a higher reality. He asks the members of his TV audience to lay their hands on their TV screens in unison in order to commune with God—to join together in what he calls a "game" that will give everyone the consoling impression of making contact, together, with the ultimate transcendent referent. "So friends," Sykes says, "laugh if you will, but tonight I have a game for us to play together. A profoundly and vitally important game for us to play together tonight." His patter culminates in a three-sentence exhortation, the lines of which invoke the ideas of "meaning as use," language games, and the struggle against loneliness: "Use me, friends. Let us play the game together. I promise that no player will feel alone." Compared to the artful techniques of Markson's novel, these devices may seem clunky, but the intellectual aspiration was much the same.
It is worth noting that, in his discussions of Markson, Broom, and solipsism, Wallace was engaging throughout in what you might call a "strong misreading" of Wittgenstein's work. His explications of Wittgenstein's philosophy are not always convincing or strictly true. Highly questionable, for instance, is his assertion of what he called "the postmodern, poststructuralist" implications of the Investigations, which entail that we can't make true claims about the real world (a popular reading of Wittgenstein that many scholars hotly dispute). More straightforwardly wrong is Wallace's claim that Wittgenstein shared Wallace's own horror of the picture of the world in the Tractatus. Wallace told McCaffery that the reason Wittgenstein "trashed everything he'd been lauded for in the Tractatus" and developed the philosophy of the Investigations was that he "realized that no conclusion could be more horrible than solipsism." Wallace also contended, in "The Empty Plenum," that the impoverished role granted to ethics, aesthetics, and spiritual values in the Tractatus was "a big motivation" for its disavowal.
In truth, however, the biographical literature suggests that Wittgenstein was perfectly at ease with the solipsism of the Tractatus, as well as oddly, even mystically consoled by its suggestion that ethical, aesthetic, and spiritual truths are unutterable. As for the development of the late philosophy, it seems to have had its origins not in a fear of solipsism but rather in two deeply resonant objections: a technical criticism that the British mathematician Frank Ramsey made in 1923 about the Tractatus's treatment of the matter of "color-exclusion" and a playful challenge, posed by the Italian economist Piero Saffra, that Wittgenstein provide the "logical form" of a meaningful hand gesture.
It's possible that Wallace's own anxieties about being "trapped" in his own head colored or confused his reading of Wittgenstein—that he projected them, in philosophical terms, onto the Tractatus and the Investigations, resulting in an overemphasis on solipsism and giving Wittgenstein's treatment of the doctrine an alarmist, even hysterical cast. But given Wallace's otherwise sure-handed feel for philosophical texts, it seems likely that his distortions were at least in part intentional, offered in the service of artistic and emotional "truths." That would certainly be consistent with the ideal of fictionalized philosophy that he strove for in Broom and venerated in Wittgenstein's Mistress—a kind of writing that blended scholarly command and poetic reimagining.
Whatever the explanation for his preoccupation with solipsism in Wittgenstein, Wallace never abandoned his fixation on sealed-off people. Few readers of Infinite Jest will forget the lonely fate of the Hal Incandenza, who becomes so alienated from the world that his speech becomes unintelligible to others, or the lifeless zombiehood that befalls anyone who watches the novel's eponymous film, which is so entertaining that its viewer becomes incapable of doing anything other than watch it. But Mark Costello pointed out to me an important irony: for someone as obsessed with isolation as Wallace, he was "obviously a social novelist, a novelist of noticed details, on a near-encyclopedic scale." Where other novelists dealing with solipsism, like Markson and Beckett, painted barren images with small compressed sentences, Costello observed, "Dave tackled the issue by massively overfilling his scenes and sentences to comic bursting"—indeed to the point of panicked overstimulation. There was a palpable strain for Wallace between engagement with the world, in all its overwhelming fullness, and withdrawal to one's own head, in all its loneliness. The world was too much, the mind alone too little. "You can't be anything but contemptible living for yourself," Costello said, summing up the dilemma. "But letting the world in—that sucks too."