Studies in History and Philosophy of Modern Physics 38 (2007) 938–947 Essay review A new glimpse of John von Neumann’s thought laboratory Michael Sto¨ltzner IZWT, University of Wuppertal, GauX str. 20, D-42119 Wuppertal, Germany John von Neumann: Selected Letters Miklo´ s Re´ dei (Ed.), Providence, RI: American Mathematical Society, 2005, 301+xxxvpp., ISBN:0-8218-3776-1. Editing a collection of letters penned by a great scientist is a difficult task that can be approached in many ways. Some collections, at bottom, just offer the reader a guided tour through the archive folders, while others appear in thick volumes that contain the complete correspondence and detailed editorial notes. In preparing ‘‘the first and only substantial published collection of letters by von Neumann’’ (p. ix), Miklo´s Re´dei has steered an intermediate course. For one, the collection contains only letters by von Neumann. The guiding principle of selection was to further ‘‘our understanding of John von Neumann as a scientist—broadly interpreted—and as a public figure’’ (p. ix). Such declared focus on scientific and societal rather than personal matters notwithstanding, the letters are arranged alphabetically rather than in chronological or thematic order. Some letters form part of extensive and deep correspondences, among them the letters to Garrett Birkhoff, Kurt Go¨del, Marshall Stone, and his Hungarian friend Rudolf Ortvay, while others stand alone and deal with specific issues that brought von Neumann into contact with fellow scientists, administrators, and company representatives. Leafing through this diversity, we encounter topics and projects as diverse as technical discussions about operator theory and quantum logic, on the one side, and opinionated statements about the current political situation and speculations about the future of high- speed computation, on the other side. We also become acquainted with his personality and his style of writing. Von Neumann appears as an often charming correspondent who encourages his addressees, as a thinker who suddenly and with great enthusiasm delves ARTICLE IN PRESS www.elsevier.com/locate/shpsb 1355-2198/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.shpsb.2007.01.002 E-mail address: stoeltzn@uni-wuppertal.de.