In the early 1920s, Hans Reichenbach and Kurt Lewin presented two topological accounts of time that appear to be interrelated in more than one respect. Despite their different approaches, their underlying idea is that time order is derived from specific structural properties of the world. In both works, moreover, the notion of genidentity--i.e., identity through or over time--plays a crucial role. Although it is well known that Reichenbach borrowed this notion from Kurt Lewin, not much has been written about their (...) relationship, nor about the way Lewin implemented this notion in his own work in order to ground his topology. This paper examines these two early versions of the topology of time, and follows the extent of Lewin’s influence on Reichenbach’s proposal. (shrink)

Recently, Michael Friedman has claimed that virtually all the seeds of Hempel’s philosophical development trace back to his early encounter with the Vienna Circle (Friedman 2003, 94). As opposed, however, to Friedman’s view of the principal early influences on Hempel, we shall see that those formative influences originated rather with the Berlin Group. Hempel, it is true, spent the fall term of 1929 as a student at the University of Vienna, and, thanks to a letter of recommendation from Hans Reichenbach, (...) he even attended some sessions of the Vienna Circle. But he spent much less time in Vienna than in Berlin, where he studied under Reichenbach from 1926 till 1933 and wrote a dissertation on probability, Reichenbach’s specialty. Hempel also attended seminars conducted by Walter Dubislav, another member of the Berlin Group. (shrink)

Sofern man die Existenz objektiver Erkenntnisse anerkennt, ist man mit der Frage nach den Bedingungen der Möglichkeit für diese Erkenntnisse konfrontiert. Der Grund muss in Voraussetzungen liegen, die selbst wiederum empirisch nicht zu rechtfertigen sind. Zwar verwerfen Popper und Carnap den Begriff des "synthetischen Urteils a priori", doch die Voraussetzung, dass es "in der Natur gesetzlich zugeht", räumen beide ein. Diese empirisch nicht zu rechtfertigende Prämisse ist ein synthetisches Urteil a priori. Gemäß Kant ist innerhalb der Klasse der Erkenntnisse a (...) priori zwischen reinen und nicht-reinen Erkenntnissen a priori zu unterscheiden. Es in vorliegender Arbeit argumentativ dafür plädiert, Naturgesetze als apriorische Erkenntnisse zu betrachten, die der Klasse der nicht-reinen synthetischen Urteile a priori zuzurechnen sind. Vor diesem Hintergrund kommt die Arbeit zu der Schlussthese: Ein empirischer (d. h. empirische Begriffe enthaltender) Satz (etwa ein Naturgesetz) kann über den (empirisch nicht einlösbaren, aber als Postulat durchaus sinnvollen) Anspruch auf allgemeine und notwendige Geltung verfügen und somit Bedingungen der Möglichkeit für objektive Erkenntnis formulieren. Doch sind für die Entdeckung empirischer Sätze mit Anspruch auf allgemeine und notwendige Geltung empirische Studien (etwa das physikalische Experiment) erforderlich. (shrink)

In his ontological works Kurt Grelling tries to give a rigorous analysis of the foundations of the so-called Gestalt-psychology. Gestalten are peculiar emergent qualities, ontologically dependent on their foundations, but nonetheless non reducible to them. Grelling shows that this concept, as used in psychology and ontology, is often ambiguous. He distinguishes two important meanings in which the word “Gestalt” is used: Gestalten as structural aspects available to transposition and Gestalten as causally self-regulating wholes. Gestalten in the first meaning are, according (...) to Grelling, “equivalence classes of correspondences”, while Gestalten as self-regulating wholes have more to do with relations of ontological dependence. Grelling’s clarification of the concept of Gestalt is doubtless an excellent piece of philosophical analysis, but at the end of the day it turns out that his analysis captures at best only a part of intuitions traditionally connected with the notion of Gestalt. (shrink)

Jakob Friedrich Fries (1773–1843) was the most prolific German philosopher of science in the nineteenth century who strived to synthesize Kant’s philosophical foundation of science and mathematics and the needs or practised science and mathematics in order to gain more comprehensive conceptual frameworks and greater methodological flexibility for those two disciplines. His original contributions anticipated later developments, to some extent, though they received comparatively little notice in the later course of the nineteenth century—a fate which partly can be explained by (...) the unfortunate development of the so-called ‘First Friesian School,’ founded by E. F. Apelt, M. J. Schleiden and O. X. Schlömilch. This situation changed temporarily when Leonard Nelson (1882–1927) arrived on the philosophical stage and founded a second, so-called, ‘New Friesian School’ in 1903. In the following two decades, Fries’ specific transformation of Kantian philosophy gained influence within the vigorous discussions about ‘new’ foundations of mathematics and, thus, also played a role within the Berlin Group surrounding Hans Reichenbach, though his work had no direct impact on the philosophy of physics being expounded therein. -/- This essay will first outline some characteristics of Fries’ development of the Kantian approach. Then it will point out the limited impact of the ‘New Friesian School’ on the Berlin Group, while highlighting some missed chances for fruitful exchange. As the originality of this school and its importance for the development of logic and philosophy of mathematics—by and large merits of its early members Walter Dubislav and Kurt Grelling —is dealt with in separate chapters of this volume, and elsewhere, this article will focus on what Fries called the ‘mathematical philosophy of nature’ (i. e. the philosophical foundations of physics). More specifically, it will show how the New Friesian School reacted to Einstein’s theories of relativity, in a way that contrasts with the approach of the Berlin Group. This discussion about relativity will also be used to reveal different understandings of the nature of ‘scientific philosophy’ in general, as well as different models of how philosophy and the empirical sciences should interact. (shrink)