Available here for the first time in English, "Reality and Its Order" is a remarkable philosophical text by Werner Heisenberg, the father of quantum mechanics and one of the leading scientists of the 20th century. Written during the wartime years and initially distributed only to his family and trusted friends, the essay describes Heisenberg's philosophical view of how we understand the natural world and our role within it. In this volume, the essay is introduced by the physicist Helmut Rechenberg and annotated by the science historian Ernst Peter Fischer. The content, particularly within its historical context, will be of great interest to many physicists, philosophers and historians of science.

Werner Heisenberg (born 1901 in Würzburg/Germany - died 1976 in München) is one of the leading scientists of the 20th century, inventor of quantum mechanics and Nobel Prize Winner. Heisenberg studied physics with Arnold Sommerfeld in Munich and with Max Born in Göttingen and worked as assistant to Niels Bohr in Copenhagen. On the island of Helgoland in 1925, he made the breakthrough to a theory of the atom, dubbed Quantum Mechanics. In 1927, he found that in the atomic world, there are limits to our knowledge, which he specified as the Uncertainty Relation. In 1933, he received the Nobel Prize as "creator of the theory of Quantum Mechanics". From 1945, he was director of the Max Planck Institute for Physics and president of the Humboldt Foundation. Konrad Kleinknecht (born 1940 in Ravensburg) is professor of experimental Physics at the Johannes-Gutenberg University of Mainz and member of the excellence cluster "Universe" at the Ludwig-Maximilians-Universität München. He has worked at the universities of Heidelberg, Dortmund, Mainz and Munich, at the European Laboratory for Elementary Particle Physics CERN in Geneva/Switzerland, Caltech in Pasadena and Fermilab near Chicago and gave the Loeb lectures at Harvard.