The Philosophy of the Physicists
Obituary Notice for Erhard Scheibe
(Brigitte Falkenburg, TU Dortmund. Translation: Michael Hallett, McGill University)

The world of philosophy, especially philosophy of science, will lament the passing on the 7 January 2010 of Erhard Scheibe after a long illness. He was 82. From 1982 until his retirement and nomination as Emeritus Professor, Scheibe was the holder of a then newly-founded Chair of Philosophy at Heidelberg, one dedicated to philosophical issues concerning the formal and natural sciences.

Erhard Scheibe was born on September 24, 1927, in Berlin, just a few days after the physicist Niels Bohr gave the famous lecture which sparked the Bohr-Einstein debate on the nature of quantum mechanics. And indeed at the centre of Scheibe’s work throughout his life stood philosophical problems with relativity and quantum theories. He began his studies in Göttingen after the Second World War, concentrating on mathematics, physics and philosophy, and belonged there to the circle of young scholars gathered around Carl-Friedrich von Weizsäcker. He received his doctorate in 1955 with a thesis in mathematics, and then proceeded to Hamburg as von Weizsäcker’s Assistent, receiving there his Habilitation in 1963 with a philosophical study of quantum mechanics. A year later, he received a call to Göttingen as Professor of Philosophy, where he occupied himself above all with the structure of physical theories.

In 1973, he published his famous book, The Logical Analysis of Quantum Mechanics, which begins with a crystal clear presentation of Bohr’s philosophy of ‘complementarity’, and ends with a formal analysis of the thought experiment of Einstein, Podolsky and Rosen, a thought experiment which can be seen as the high point of the Bohr-Einstein debate. Lectures and essays followed, covering themes from Plato to Leibniz, Kant and modern science. His reputation grew, and he became, not just one of the most important philosophers of the exact sciences, but one who shaped the philosophy of science in the German speaking world. He was, perhaps, not as generally well-known outside Germany as the significance and depth of his work merited. But experts knew, a fact which is testified to by the frequency with which he was invited to international conferences, and also by the number of young scholars who came to study with him under the auspices of the Humboldt Stiftung.
Once established in Heidelberg, Scheibe turned his attention more to the historical and conceptual background of physics. In both research and teaching, he sought to investigate the characteristic way the physics of the 20th century had combined both rationalism and empiricism. The book Die Reduktion physikalischer Theorien [The Reduction of Physical Theories] appeared in two volumes in 1997 and 1999; this is surely Scheibe’s central work, a monumental investigation of the unity of physics in the face of apparently incommensurable theories; whoever is to profit from a study of this must bring to it at the very least a sound knowledge of the mathematical and logical foundations of modern theoretical physics.

It is a sign of Scheibe’s engagement as a teacher, but perhaps also of the worsening situation as regards German university research, that he was able to complete this work only with the freedom which retirement brings. A collection of the most important of his papers and lectures, Between Rationalism and Empiricism: Selected Papers in the Philosophy of Physics, followed in 2001. His last book, Die Philosophie der Physiker [The Philosophy of the Physicists] appeared in 2006, a book wrested from the ravages of a increasingly debilitating illness. The presentation it gives of the philosophical convictions of the most important physicists of the 20th century became an enormous success. It is now to be read, it seems, as an appropriate legacy of Erhard Scheibe.