The search for a quantum theory of the gravitational field is one of the great open problems in theoretical physics. This book presents a self-contained discussion of the concepts, methods and applications that can be expected in such a theory. The two main approaches to its construction - the direct quantisation of Einstein's general theory of relativity and string theory - are covered. Whereas the first attempts to construct a viable theory for the gravitational field alone, string theory assumes that (...) a quantum theory of gravity will be achieved only through a unification of all the interactions. However, both employ the general method of quantisation of constrained systems, which is described together with illustrative examples relevant for quantum gravity. There is a detailed presentation of the main approaches employed in quantum general relativity: path-integral quantisation, the background-field method and canonical quantum gravity in the metric, connection and loop formulations. The discussion of string theory centres around its quantum-gravitational aspects and the comparison with quantum general relativity. Physical applications discussed at length include the quantisation of black holes, quantum cosmology, the indications of a discrete structure of spacetime, and the origin of irreversibility. This book will be of interest to researchers and students working in relativity and gravitation, cosmology, quantum field theory and related topics. It will also be of interest to mathematicians and philosophers of science. (shrink)

Dieser Buchtitel ist Teil des Digitalisierungsprojekts Springer Book Archives mit Publikationen, die seit den Anfängen des Verlags von 1842 erschienen sind. Der Verlag stellt mit diesem Archiv Quellen für die historische wie auch die disziplingeschichtliche Forschung zur Verfügung, die jeweils im historischen Kontext betrachtet werden müssen. Dieser Titel erschien in der Zeit vor 1945 und wird daher in seiner zeittypischen politisch-ideologischen Ausrichtung vom Verlag nicht beworben.

A scholarly edition of a work by David Hume. The edition presents an authoritative text, together with an introduction, commentary notes, and scholarly apparatus.

A new study of the mathematical-physical mode of cognition.

For some time now I have been arguing that Fichte's theory can be read as circular, antifoundationalist, and systematic, and further arguing that it is the source of an epistemological revolution in philosophy. Fichte and most of his interpreters mainly see him as carrying forward the critical philosophy. But I see him as breaking with it in crucial ways in a profoundly innovative theory. The aim of this paper is to pull together aspects of this argument in a single place (...) in order to describe Fichte's theory as I see it, using a wider range of texts than I have so far employed, drawing consequences that follow from my interpretation and responding to recent criticism of it. In so doing, I intend to reaffirm my conviction that the interest of Fichte's theory is not merely archival, something historians of philosophy are interested in because they cannot do philosophy, or something that philosophers might concern themselves with when they are not concerned with philosophy, but directly relevant to the contemporary discussion. But as I see it, the contemporary relevance of the Fichtean view largely depends on an unorthodox, anti-foundationalist reading of it. For if it is read in an orthodox, Cartesian, foundationalist manner, favored by most writers on Fichte, it has nothing or almost nothing to contribute to our increasingly anti-foundationalist debate on knowledge. (shrink)

1. Die Lehre vom Primat der praktischen Vernunft.

1. Die Lehre vom Primat der praktischen Vernunft.

This paper is concerned to take a closer look at the relations between Paul Tillich and Fritz Medicus, his philosophical teacher in Halle. The center of attention is on their orientation within neo-Kantianism and the Fichte and Schelling renaissance. A collection of letters and other documents reflects their involvement in events of contemporary history, their respective literary works, and an ongoing friendship.

Im "System der Sittenlehre" fand Fichtes praktische Philosophie im direkten Anschluß an die Wissenschaftslehre von 1794 ihre vollendete Gestalt. Fichtes theoretischer Ansatz bietet den bis heute einzigen methodisch konsistenten Versuch einer Letztbegründung des Sollens als Beweis der sittlichen Freiheit des Einzelnen.

Weinberg's 1972 work, in his description, had two purposes. The first was practical to bring together and assess the wealth of data provided over the previous decade while realizing that newer data would come in even as the book was being printed. He hoped the comprehensive picture would prepare the reader and himself to that new data as it emerged. The second was to produce a textbook about general relativity in which geometric ideas were not given a starring role for (...) (in his words) too great an emphasis on geometry can only obscure the deep connections between gravitation and the rest of physics. (shrink)

Johann Gottlieb Fichte: Über den Begriff der Wissenschaftslehre oder der sogenannten Philosophie Erstdruck: Weimar (Industrie-Comptoir) 1794. Der Text folgt der zweiten vermehrten und verbesserten Ausgabe: Jena (Gabler) 1798. Textabweichungen gegenüber der Erstausgabe sind in den Fußnoten wiedergegeben. Der in der Erstausgabe enthaltene dritte Abschnitt »Hypothetische Eintheilung der Wissenschaftslehre« wurde in der zweiten Ausgabe gestrichen, da er durch Fichtes inzwischen erschienene »Grundlage der gesamten Wissenschaftslehre« (1794/95) überflüssig geworden war. Die der zweiten Ausgabe beigefügten Rezensionen (zu Schellings Schrift »Über die Möglichkeit der (...) Form einer Philosophie überhaupt« und zu Fichtes »Über den Begriff der Wissenschaftslehre« aus Jacobs »Philosophischen Annalen«) wurden nicht mit aufgenommen. Vollständige Neuausgabe mit einer Biographie des Autors. Herausgegeben von Karl-Maria Guth. Berlin 2014. Textgrundlage ist die Ausgabe: Johann Gottlieb Fichtes sämmtliche Werke. Herausgegeben von I. H. Fichte, Band 1-8, Berlin: Veit & Comp., 1845/1846. Die Paginierung obiger Ausgabe wird in dieser Neuausgabe als Marginalie zeilengenau mitgeführt. Umschlaggestaltung von Thomas Schultz-Overhage. Gesetzt aus Minion Pro, 11 pt. (shrink)