The Murder of Professor Schlick

The Rise and Fall of the Vienna Circle

David Edmonds

• Publisher: Princeton University Press
• Year: 2020
• ISBN:
  9780691185842
• Topic: Filosofia
• Subtopic: Storia e teoria della filosofia

From the author of Wittgenstein's Poker and Would You Kill the Fat Man?, the story of an extraordinary group of philosophers during a dark chapter in Europe's history On June 22, 1936, the philosopher Moritz Schlick was on his way to deliver a lecture at the University of Vienna when Johann Nelböck, a deranged former student of Schlick's, shot him dead on the university steps. Some Austrian newspapers defended the madman, while Nelböck himself argued in court that his onetime teacher had promoted a treacherous Jewish philosophy. David Edmonds traces the rise and fall of the Vienna Circle—an influential group of brilliant thinkers led by Schlick—and of a philosophical movement that sought to do away with metaphysics and pseudoscience in a city darkened by fascism, anti-Semitism, and unreason.The Vienna Circle's members included Otto Neurath, Rudolf Carnap, and the eccentric logician Kurt Gödel. On its fringes were two other philosophical titans of the twentieth century, Ludwig Wittgenstein and Karl Popper. The Circle championed the philosophy of logical empiricism, which held that only two types of propositions have cognitive meaning, those that can be verified through experience and those that are analytically true. For a time, it was the most fashionable movement in philosophy. Yet by the outbreak of World War II, Schlick's group had disbanded and almost all its members had fled. Edmonds reveals why the Austro-fascists and the Nazis saw their philosophy as such a threat. The Murder of Professor Schlick paints an unforgettable portrait of the Vienna Circle and its members while weaving an enthralling narrative set against the backdrop of economic catastrophe and rising extremism in Hitler's Europe.

 

1

Prologue

GOODBYE, EUROPE

DEPENDING ON how you look at it, the timing was either fortunate or ill-fated.

The Fifth International Congress for the Unity of Science met at Harvard from 3–9 September 1939. On 1 September 1939, German tanks had crossed into Poland: Britain and France had treaties with Poland guaranteeing its borders. Two days after the German invasion, Poland’s two Western allies responded by declaring war on Germany. The Congress opened, then, just as World War II began.

On the evening of the first day, the delegates listened to President Franklin D. Roosevelt’s radio address from the White House. He assured listeners that he did not intend the United States to become involved in hostilities. “I have said not once but many times that I have seen war and that I hate war. I say that again and again. I hope the United States will keep out of this war. I believe that it will. And I give you assurance and reassurance that every effort of your Government will be directed toward that end.”

Given the enormity of the events that were unfolding, a conference on the philosophy of science must have felt inconsequential, if not downright inappropriate. But for some of the participants, the staging of the conference that week was both lucky and life-changing—in fact, life-saving.

The scientist and philosopher Richard von Mises, whose brother was another renowned academic, the economist Ludwig von Mises, had traveled to Boston from Turkey. He did not go back. The Polish logician Alfred Tarski also stayed on, having embarked on the last ship to leave Poland before the German invasion. Apparently oblivious to the imminence of the threat to his homeland, he had the wrong visa (it was for a temporary visitor) and no winter clothing. Rather more important was that he was now cut off from his family in Warsaw. But had he not accepted the invitation to participate in the Congress, he would most likely have shared the fearful destiny of three million fellow Polish Jews.

Other speakers at this Harvard conference had left Europe in previous years. There to greet Tarski as he disembarked from the boat in New York was German-born philosopher Carl Gustav (Peter) Hempel. Hempel had been a student of the philosopher of science Hans Reichenbach, who had arrived in America in 1938 and was also present for the Congress. Rudolf Carnap, gentle in personality, colossal in stature—and about whom we’ll be hearing much more—had left for the US in December 1935. Philipp Frank, physicist and philosopher, had been based in the States for a year, after moving from Prague. Edgar Zilsel, considered a sociologist of science, had still been in Austria at the time of the Anschluss, the takeover of Austria by Germany in 1938, and was able to bring eyewitness testimony of the savagery the Nazis had unleashed. So too was the philosopher of law Felix Kaufmann. Because he had financial resources, Kaufmann had, naïvely, felt shielded from anti-Semitism, and left his escape until the last moment. Meanwhile, the most colorful character of them all, Otto Neurath, had arrived from The Hague, where he had recently taken up residence after fleeing Vienna in 1934. A contemporary Time magazine article painted him as a “bald, booming, energy-oozing sociologist and scientific philosopher.”¹ Although his friends urged him to stay in the US, his immediate priority was to return to the Netherlands, and to the woman who would become his third wife.

In all there were some two hundred participants. The first sessions of the conference were focused on whether the sciences could be unified: What did the natural sciences, such as physics, have in common with the social sciences, such as psychology and sociology? Could they be placed on the same foundations, and how firm were these foundations? Beyond these issues, an eclectic range of other topics was discussed, including probability, truth, psychology, infinity, logic, the history and sociology of science, and the foundations of physics.

Much of the groundbreaking work in these areas had originated in Europe, specifically from Vienna. The conference had been organized by Neurath and Charles Morris, a Chicago-based philosopher with close links to the Vienna Circle and an enthusiast for bringing its ideas to the United States. American philosopher W.V.O. Quine wrote of the gathering in Harvard that it was basically “the Vienna Circle, with accretions, in international exile.”² He himself was a vital accretion.

The Vienna Circle—and its so-called logical empiricism—had come to occupy a commanding position in the world of philosophy in general and in the philosophy of science in particular. The Circle had had a bold project. It had tried to marry an old empiricism with the new logic. It had wanted to carve out a role for philosophy in assisting science. It believed scientific propositions could be known and meaningful, and that this was what distinguished genuine propositions from pseudo-propositions; this was what demarcated science from metaphysics. It had included many brilliant thinkers, including Kurt Gödel, widely acknowledged to be the most significant logician of the twentieth century, and was linked to many others, including two of the most important philosophers of the twentieth century, Ludwig Wittgenstein and Karl Popper.

As the Harvard conference got under way, Europe was accelerating its descent into barbarity, with every day bringing acts of violence and cruelty that over the next six years would become routine. On 3 September, in the village of Truskolasy, in southern Poland, dozens of peasants were rounded up and shot. Just fifty miles away, twenty Jews were forced to assemble in the marketplace. Among them was sixty-four-year-old Israel Lewi. “When his daughter, Liebe, ran up to her father, a German told her to open her mouth for ‘impudence.’ He then fired a bullet into it.”³ The execution of each of the other Jews followed soon after. On the day the conference drew to a close, 630 Czech political prisoners were transported to Dachau concentration camp in Bavaria.

During the Harvard conference, a provocative position was adopted by Horace Kallen, a Jewish-American academic from the New School for Social Research who was famous for advocating cultural pluralism and for opposing what he regarded as oversimplified answers to philosophical problems. He advanced the view that attempting to unify the sciences was a dangerous project, linked to fascist ideology. Neurath, a distant relative of Kallen, countered that, on the contrary, unification had a democratic motivation, and would facilitate criticism of any particular specialism. Neurath was one of several Circle members who believed that logical empiricism was integral to the struggle against fascism. Logical empiricism represented Enlightenment values of reason and progress, a buffer against dark and irrational emotions. Logical empiricism represented sense against nonsense, truth against fiction. The fight was more important than ever.

Vienna had until recently been a creative cauldron. An unusual combination of political, social, and economic forces had somehow combined to produce astonishing cultural and scholarly achievements, including those of the Circle. Then the political cauldron had bubbled over. The Vienna Circle had been forcibly dissolved in 1934. Later, its leader, Moritz Schlick, was murdered.

Schlick’s killer, Johann Nelböck, a mentally unstable former student, claimed he was driven by political and ideological motives. Whether or not that was true—and it seems highly questionable—several Austrian newspapers took Nelböck at his word: logical empiricism was pernicious, antireligious, antimetaphysical. It was a Jewish philosophy, and Professor Schlick embodied all that was wrong with it. In this context, the argument ran, Nelböck’s act was not unreasonable. Indeed, one article suggested, it was even possible that Schlick’s death might facilitate the search for a solution to the “Jewish Question.”

Following Schlick’s murder the Vienna Circle continued to limp on informally. But the Anschluss and the outbreak of World War II marked points of no return. If its ideas were to survive, they would now have to take root in the Anglo-American world. That was a project for the future.

So what was the Vienna Circle, the “republic of scholars,”⁴ as Otto Neurath once described it, and why did it matter? Why had it been crushed by the authorities? Why had its members been forced into exile? And had it succeeded in its ultimate ambition—to vanquish metaphysics and banish the multiple varieties of pseudo-knowledge?

2

Little Rooster and the Elephant

The empiricist does not say to the metaphysician “what you say is false” but, “what you say asserts nothing at all!”

—MORITZ SCHLICK

IN 1905, Albert Einstein, then a doctoral student of physics working as a clerk in a Swiss patent office, published four papers as well as his dissertation. The year 1905 is known by scientists as Einstein’s annus mirabilis—a miraculous year, for these papers gave the world E = mc², the special theory of relativity, and the claim that light must have particle-like as well as wave-like properties. The classical physics of Isaac Newton and James Clerk Maxwell was toppled. A new era of (at times) highly counterintuitive science had begun. In particular, time and space were not constants; they were relative, because they depended upon the observer who was measuring them.

Einstein would not become a household name for another decade and a half. But among those quick to grasp the magnitude of his breakthroughs was a young, serious, articulate, bespectacled, mustachioed mathematician and philosopher named Hans Hahn, or Hänchen (Little Rooster) to his friends, an ironic nickname for a tall man.

Hahn was the originator of what would become known as the Vienna Circle. He was born in Vienna into a middle-class family in 1879 (his Jewish father was a journalist, then high-ranking in the civil service) and studied at the University of Vienna, initially law, before he turned to mathematics, receiving both a doctorate and the higher doctoral degree, the habilitation. He would become a figure of international standing after whom various complex theorems are now named, including the Hahn embedding theorem and the Hahn decomposition theorem. He would also become an important recruiting agent for the Vienna Circle: some of his students would surpass him in their impact on the world stage, most notably Kurt Gödel.

From 1907 Hahn began to hold regular meetings with a small set of other young, Jewish, postdoctoral, scientifically inclined, Vienna-based philosophers—usually in a coffeehouse—to mull over the philosophical foundations of science as well as “a great variety of political, historical, and religious problems.”¹ Besides Hahn, there was Otto Neurath, who had been awarded his doctorate in Berlin, and Philipp Frank, the junior among them at twenty-three, a short man who walked with a limp after having been hit by a streetcar and who was already churning out academic papers, many on relativity. On occasion they were possibly joined too by scientist Richard von Mises, a close friend of both Hahn and Frank. These men discussed the French mathematicians/physicists Pierre Duhem and Henri Poincaré as well as philosopher and scientist Ernst Mach. They were all fascinated and puzzled by the transformations under way in theoretical physics. They were interested in the methodology of science, the language of science, the claims and status of science, and the distinction between science and pseudo-science. They wished to demarcate the empirical sciences—involving experiments and evidence—from other forms of inquiry. They were interested in the foundations of geometry and mathematics. They wanted to understand how to make sense of probability. They shared the view that philosophy as traditionally practiced was needlessly esoteric and often nonsensical. They shared a belief that philosophy and science should be more collaborative, more closely linked. They wanted philosophy to be useful to science in clarifying the scientific enterprise. They had a broadly left-leaning political orientation. As we shall see, the politics and the philosophy were inextricably linked.

Their championing of progressive politics and the new science was hardly likely to appeal to supporters of the pre–World War I status quo. Vienna at the time was part of the Austro-Hungarian Empire, presided over by Franz Josef I, and Catholicism, the religion of the vast majority of the country, was a powerful cultural force, mostly hostile to social and political reform. The university too was resistant to change.

This informal discussion group met on and off until 1912. By the outbreak of World War I, in 1914, they had scattered. Hahn had married a fellow mathematician, Eleanor (Lilly) Minor, and taken a chair at the University of Czernowitz, 1,000 kilometers to the east of Vienna at the furthest edge of the Austro-Hungarian Empire (in what is now Ukraine). Von Mises became professor of applied mathematics at Strasbourg. Frank occupied the chair of theoretical physics at the German University in Prague, where he was to remain until just before World War II. Frank would return to Vienna regularly; it was his place of birth and the city he thought of as home. Hahn, von Mises, and Neurath saw action in World War I, and Hahn was shot and wounded on the Italian front, the bullet that lodged in his back never to be removed.

Pre–World War I, these precocious scholars were not confident enough to accord their little group a title, but we may regard it as the Vienna Circle in embryonic form. They did not regard themselves as either entirely original nor, yet, as fermenters of philosophical revolt. They placed themselves in a tradition—an empiricist or positivist tradition. In particular, they felt themselves to be disciples of, and heirs to, Ernst Mach.

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Mach should be most familiar as the name used when talking about the speed at which jet planes travel. A Mach number is a ratio of the speed of an object to the speed of sound (the latter will vary according to what the object is passing through, e.g., air ...