Karl Sigmund’s new book Exact Thinking in Demented Times tells the dramatic history of an intellectual revolution.

Sometime around 1900, in the spirit of interdisciplinary thinking of the day, the rectors of the University of Vienna decided to appoint physicists to teach philosophy. So they hired leading Austrian physicists Ernst Mach and Ludwig Boltzmann, who gave a scientific turn to a field usually prone to metaphysical speculation. In 1922, they were joined by a young German philosopher of physics, Moritz Schlick, who took over the chair, bringing with him a new approach shaped by Albert Einstein’s theory of relativity.

Schlick became a prophet of Einstein’s scientific revolution, and thought philosophy needed a similar intellectual transformation. Who could be the Einstein of a new kind of philosophy? For Schlick, a recently- published small book by a young philosopher, Ludwig Wittgenstein, then a primary school teacher in a small village in Lower Austria, represented such a turning point. The small book, the Tractatus, was intensely studied by Schlick and a group of students and scholars gathered around him. Influenced by Wittgenstein, the group later called the Vienna Circle transformed philosophy in the 20th century. Present day analytic philosophy, the dominant trend in contemporary studies in the field, was shaped in a central way by that intellectual revolution.

Karl Sigmund’s richly illustrated new book Exact Thinking in Demented Times tells the story of that intellectual adventure between philosophy and the sciences brilliantly, from its forerunners Mach, Boltzmann and the British logician Bertrand Russell to the tragic dissolution of the Circle in the political turmoil of rising fascism in the 1930s. A passionate intellectual history, the book embeds the innovations of Schlick, Rudolf Carnap, Otto Neurath, Wittgenstein and Kurt Gödel in the often- dramatic episodes of their lives. It is a collective biography of the Circle’s members, relating their encounters, influences and passionate clashes in a subtle way.

Precision Philosophy

book review
Exact Thinking in Demented Times:
The Vienna Circle and the
Epic Quest for the Foundations
of Science.
With a preface by Douglas Hofstadter
Basic Books
New York 2017
pp 480

Sigmund, a leading Austrian mathematician, grew up in the mythical shadow of the Vienna Circle, whose members either died or fled Austria in the 1930s, never to return. Despite their absence during and after the war, until recently their theories were still feared by conservatives and derided by the leftists close to the Frankfurt school (Theodor Adorno, Herbert Marcuse). But Sigmund felt attracted by the mathematicians who were members of the Circle; he re-edited their work and fought for their recognition.

To a mathematician, the Circle’s painstaking logical exactness and clarity, often ridiculed by philosophy colleagues, appeared as just another virtue of their thought. More recently, Sigmund initiated an exhibit on the Vienna Circle at the University in 2015, of which (full disclosure) I was a conceptual part.

The book’s lively narrative begins with Mach and Boltzmann describing their clashes, as well as the dramatic episode of Boltzmann’s suicide. Sigmund outlines the Circle’s cultural setting, its contact with architects like Adolf Loos and Josef Frank, its interaction with writers like Robert Musil, Hermann Broch or Leo Perutz and the regular presence of Viennese philosophers at the Bauhaus, then the hotspot of artistic modernism.

The role of mathematically exact thinking had a huge influence on the Vienna circle, and Sigmund draws a lively picture of the influence of mathematician Hans Hahn and the scientific breakthrough of his student Kurt Gödel, whose proof of the incompleteness of mathematics transformed the field and laid the foundations for modern computer science. As elsewhere in this intellectual history, Sigmund embeds the description of Gödel’s innovations into his biography, from his frequent stays at psychiatric hospitals and his dramatic flight from the Nazis to his close friendship with Einstein in the 1950s.

It is a masterful history of scientific exactness in interwar Austria, which combines a richness of historical detail and a clarity and simplicity in the explanations of science with the dramatic precision of the best writers of narrative. The Vienna Circle deserved no less.