Philosophy’s role in the search for truth is to examine the form of our statements, to insure that they are syntactically and logically correct. To this end, the Vienna Circle drew on the symbolic logic developed by the English philosopher Bertrand Russell, which offered a way to reduce any sentence to a series of symbols and formulas. Many pages of Carnap’s 1934 book, “The Logical Syntax of Language,” look as if they could have come from a math textbook.
Symbolic logic is useful because statements can go wrong in ways that ordinary usage makes it hard to detect. In most cases, determining whether a statement is empirically true or false is fairly straightforward. If someone says that the moon is made of green cheese, there are various ways to check: you could look at the moon through a telescope, or examine a moon rock, or calculate how a moon-size ball of green cheese would behave in outer space. Even if false, “The moon is made of green cheese” is still a meaningful proposition, because it makes an assertion about the world that can be tested.
Some statements, however, can’t be proved true or false, because they are constructed in a way that violates the rules of language. Carnap labelled these “pseudo-statements”—“a sequence of words [that] looks like a statement at first glance,” but whose syntax or vocabulary renders it meaningless. He gave as an example “Caesar is and”: if someone said this to you, you wouldn’t say that she was right or wrong, just that she didn’t know English syntax.
For the Vienna Circle, the best hunting ground for pseudo-statements was metaphysics, the branch of philosophy that deals with fundamental concepts like being and essence, time and space. Since Aristotle, who called it “first philosophy,” metaphysics had been seen as the highest and most disinterested form of thought. For Immanuel Kant, it was “the queen of all the sciences.” But, for the members of the Vienna Circle, metaphysics was a queen like Marie Antoinette—imperious, out of touch, and ripe for the guillotine.
The problem with metaphysical statements is that they are generally unverifiable, which to the logical empiricists meant they are meaningless. In Carnap’s 1932 essay “The Elimination of Metaphysics Through Logical Analysis of Language,” he asks us to imagine a man who invents a new adjective, “teavy,” and who, when we ask him how to tell whether or not something is teavy, replies that “there are no empirical signs of teavyness.” In that case, Carnap says, “we would deny the legitimacy of using this word.”
The same principle, he argues, should apply to metaphysical terms, from Plato’s “Idea” to Kant’s “thing-in-itself.” Such impressive words may provoke “associated images and feelings,” Carnap writes, but they have no actual meaning, so any explanation that relies on them is saying nothing at all.
Metaphysics wasn’t just a ghost from the past to be exorcised; it was still on the march, with important consequences for both philosophy and politics. Carnap’s essay was written as an attack on Martin Heidegger, the other great German-language philosopher to emerge after the First World War. If Wittgenstein’s “Tractatus” is a fundamental work of analytic philosophy, Heidegger’s 1927 book, “Being and Time,” is equally important for “Continental” philosophy—a catchall term used by the Anglo-American analytic school to refer to all those benighted Europeans who still take metaphysics seriously.
Heidegger and Wittgenstein shared an ability to inspire awe and devotion, but in most respects the two were opposites. Wittgenstein was raised in privilege in Vienna; Heidegger grew up poor in Messkirch, a small town in rural Germany, where his father was the sexton of the Catholic church. Wittgenstein was a wanderer who moved back and forth between Austria and England, and between academia and other pursuits; Heidegger spent his entire career at the German university where he had been a student, and did his thinking in a remote cabin he built in the Black Forest. (That cabin, the most famous dwelling in twentieth-century philosophy, is the subject of its own book, “Heidegger’s Hut,” by Adam Sharr.)
Above all, the two men differed in their opinion of the value of metaphysics. In 1929, the year that the Vienna Circle published its manifesto, Heidegger delivered a lecture whose title, “What Is Metaphysics?,” was a red rag waved in the face of the logical empiricists. Indeed, he began by acknowledging that modern science has no use for metaphysics. According to the scientific conception of the world, only things we can experience directly are real; the domain of knowledge is “beings themselves—and nothing besides.”
The second part of that statement, he argues, far from being a throwaway phrase, reveals a fundamental truth: in addition to beings, there is the nothing. We come to understand the nothing not through reason but through the experience of anxiety; in moments of existential angst, “beings as a whole slip away, so that just the nothing crowds round.” It is only because we encounter the nothing in this primal way that we are able to understand logical concepts like negation and nonexistence. As Heidegger puts it, “das Nichts selbst nichtet”—a strange phrase that English translators have rendered as “the nothing itself nihilates,” or even “the nothing itself noths.”
For Heidegger’s many admirers, his dislocation of language gave metaphysical concepts back the power and strangeness they had lost over the millennia. The way he roots philosophy in mood, rather than in mere intellection, makes his work imaginatively engaging in ways that logical empiricism can’t achieve. One might say that Heidegger wanted to make philosophy more like poetry, whereas the Vienna Circle wanted it to be more like math. For Carnap, the poetic dimension of Heidegger’s thought was precisely the issue, since it depended on misusing language to create an illusion of profundity. The problem, he writes in “The Elimination of Metaphysics,” is grammatical: because German (like English) treats the word “nothing” as a noun, it can be used as the subject of a sentence. For instance, if someone asks, “What is outside?,” you might reply, “Nothing is outside,” just as you could say, “Rain is outside.” This creates the illusion that “nothing” is an entity like rain, whose properties and actions can be described. Syntactically, “The nothing reveals itself” seems to be the same kind of statement as “The rain falls down.”
This is exactly the kind of error we need logic to rescue us from. When we say “Nothing is outside,” Carnap argues, we’re using a kind of verbal shorthand; what we really mean is “There does not exist anything which is outside.” Phrasing it this way shows that the word “not” can properly be used only to negate a proposition. Using it as the subject of a proposition, as Heidegger does, is at best a sign of mental confusion, and at worst a deliberate attempt to mystify and mislead.
Indeed, in “What Is Metaphysics?,” Heidegger explicitly says that he wants to get rid of logical thinking, so that “the very idea of ‘logic’ dissolves in the whirl of a more basic questioning.” This was the fundamental disagreement that separated Heidegger from the Vienna Circle: he believed that language could discover truths deeper than logic; the Circle believed that language without logic could yield only nonsense. As Wittgenstein warned in the last sentence of the “Tractatus,” “Whereof one cannot speak, thereof one must be silent.”
Whereof the Vienna Circle could speak, however, it had a lot to say. Its 1929 manifesto gave rise to a new journal, a series of conferences to bring together leaders in various scientific fields, and an International Encyclopedia of Unified Science, which aimed to summarize all of scientific knowledge in two hundred volumes. Still more broadly, the manifesto announced that logical empiricism entailed a particular approach to “questions of life”: “Endeavors toward a new organization of economic and social relations, toward the unification of mankind, toward a reform of school and education, all show an inner link with the scientific world-conception; it appears that these endeavors are welcomed and regarded with sympathy by the members of the Circle, some of whom indeed actively further them.”
That was certainly true of Otto Neurath, one of the main authors of the manifesto and the most vivid personality in the Circle. Neurath, a committed leftist who had participated in the failed revolution in Munich in 1919, was an adept publicist of ideas. He was the one who named the group, hoping, in the words of a fellow member, Philipp Frank, to evoke “other things on the pleasant side of life,” such as Viennese waltzes. When he wasn’t philosophizing, Neurath worked on public housing, adult-education programs, and a new method of representing data in easily comprehensible pictograms, known as Isotype, which resulted in the visual vocabulary now used in infographics throughout the world.
But not everyone in the Circle was happy to be dragged into political debates—including Schlick, whom the manifesto was intended to honor. Edmonds brings to life the volatile political and cultural scene in nineteen-twenties Austria, a small country created after the First World War out of the German-speaking lands of the former Habsburg Empire. Vienna, a city of two million people, had been the right size for the capital of a far-flung multinational state, but now it found itself in a country of just 6.5 million people.
“Red Vienna,” as it was nicknamed, had a socialist government, a cosmopolitan culture, and a large Jewish population. All three aspects made it thoroughly hated by the rest of the country, which was rural, conservative, and Catholic. Austria came to the brink of civil war in the twenties, and in 1933 it became a fascist dictatorship under the rule of the Fatherland Front. In these circumstances, the Vienna Circle had much to lose from becoming publicly identified with the left.
In 1934, the group came under scrutiny from the police, prompting Schlick to write letters to state agencies insisting that it was “absolutely unpolitical.” The letters didn’t help; the Circle’s official sponsoring organization was dissolved, and some members were forced out of their jobs or arrested. Though the annexation of Austria by Nazi Germany was still four years away, the members of the Circle began to look for opportunities to emigrate.
Many ended up in America, where they helped shape the next generation of academic philosophers. Herbert Feigl went to the University of Iowa in 1931; Carnap was hired by the University of Chicago in 1936. Kurt Gödel, famous for his “incompleteness theorem” and his complete unworldliness, didn’t wake up to the danger until the Second World War began. After receiving a job offer from the Institute for Advanced Study, in Princeton, in January, 1940, he had to go the long way around, crossing the entire Soviet Union, the Pacific Ocean, and the United States to get to New Jersey.
For the lesser-known members of the group, things were tougher. Edmonds documents the struggles of Rose Rand, a Jewish woman who earned her doctorate from the University of Vienna in 1938 but couldn’t find a secure academic job in England, forcing her to rely on the grudging charity of émigré organizations. Wittgenstein intervened on her behalf, but even he found her demanding and difficult to deal with. Still, she survived, living and teaching until 1980. Remarkably, no one from the Circle was killed by the Nazis.
Meanwhile, as the logical empiricists fled for their lives, Heidegger was on the rise. After Hitler’s takeover in Germany, in 1933, the philosopher was appointed rector of the University of Freiburg and given the responsibility of bringing it into alignment with Nazism. An enthusiastic Nazi, Heidegger saw his task in metaphysical terms, declaring in his inaugural address that the essence of science is “the questioning standing of one’s ground in the midst of the constantly self-concealing totality of what is.” Carnap would have scoffed at this language; but as the Vienna Circle knew, and Germany and the world were about to find out, pseudo-statements can have very real consequences.♦