In a previous paper we have shown that in quantum chromodynamics the gluon propagator vanishes in the infrared limit, while the ghost propagator is more singular than a simple pole. These results were obtained after angular averaging, but in the current paper we go beyond this approximation and perform an exact calculation of the angular integrals. The powers of the infrared behaviour of the propagators are changed substantially. We ﬁnd the very intriguing result that the gluon propagator vanishes in the (...) infrared exactly like p2, whilst the ghost propagator is exactly as singular as 1/p4. We also ﬁnd that the value of the infrared ﬁxed point of the QCD coupling is much decreased from the y-max estimate: it is now equal to 4π/3. Following a recent study by von Smekal et al., we analyzed in Ref. the coupled Dyson- Schwinger equations for the gluon and ghost form factors F and G. The approximations were two-fold: ﬁrstly the vertices were taken bare, and secondly angular averaging was introduced (the so-called y-max approximation). Deferring to later work an improvement of the vertices. (shrink)
This paper proposes a biosemiotic conception of theories, as non-intentional organic theories, which is based on an analysis and comparison of philosopher Norwood Russell Hanson’s account of theories and zoologist Jakob von Uexküll’s theory of organisms. It is argued that Hanson’s proposals about scientific theories and their relation to observation are semiotic in nature and that there exists a correspondence between Hanson’s depiction of the relationship between theories, observation, and reality and von Uexküll’s views on the relationship between organisms and (...) their environments. This correspondence supports an account of theories that depicts them as organic extensions of our perceptual physiology. Among the epistemological consequences of this account are the following: The kind of correspondence that is established through theories between a subject and reality is related rather to a subject’s actions than to a faithful representation of every aspect of the world, it suggests a strong emphasis on the creative aspects of knowledge acquisition, and it urges a reassessment of the evolutionary epistemology of theories. (shrink)
The fragments of the Peripatetic philosopher and mathematician in a scholarly edition. Greek texts are joined to a German commentary setting each fragment in historical and philosophical context. The volume is the eighth of a series comprehending the Peripatetic school. Bibliography included.--C. B.
The ethics of Aristotle , and virtue ethics in general, have enjoyed a resurgence of interest over the past few decades. Aristotelian themes, with such issues as the importance of friendship and emotions in a good life, the role of moral perception in wise choice, the nature of happiness and its constitution, moral education and habituation, are finding an important place in contemporary moral debates. Taken together, the essays in this volume provide a close analysis of central arguments in (...)Aristotle's Nicomachean Ethics and show the enduring interest of the questions Aristotle raises. (shrink)
Diese Veröffentlichung des verdienten Forschers entstand auf der Grundlage seines Vortrags auf dem 8. Internationalen Kolloquium über Gregor von Nyssa 1998 in Paderborn. Der Beitrag auf dem Gregorkolloquium wurde auf Anregung und mit Unterstützung von Hubertus R. DROBNER zur Monographie ausgebaut und herausgegeben. Die detaillierte und umfassende Darbietung des Quellenmaterials zu den entscheidenden Fragen der Gregorforschung, die das Buch von Lilla leistet, macht das Anliegen des Herausgebers verständlich. Es gelingt dem Autor, die Quellenforschung mit der geistesgeschichtlichen Betrachtung der Problematik zu (...) einer spannenden Darstellung zu verbinden, womit er das gegebene Versprechen uneingeschränkt einlöst. Darüber hinaus stellt die Studie von LILLA eine wertvolle Vervollständigung des Quellenapparats zu der Textausgabe von De Beatitudinibus von John F. CALLAHAN in Gregorii Nysseni Opera aus dem Jahr 1992 dar. (shrink)