We model scientific theories as Bayesian networks. Nodes carry credences and function as abstract representations of propositions within the structure. Directed links carry conditional probabilities and represent connections between those propositions. Updating is Bayesian across the network as a whole. The impact of evidence at one point within a scientific theory can have a very different impact on the network than does evidence of the same strength at a different point. A Bayesian model allows us to envisage and analyze the (...) differential impact of evidence and credence change at different points within a single network and across different theoretical structures. (shrink)

Our scientific theories, like our cognitive structures in general, consist of propositions linked by evidential, explanatory, probabilistic, and logical connections. Those theoretical webs ‘impinge on the world at their edges,’ subject to a continuing barrage of incoming evidence. Our credences in the various elements of those structures change in response to that continuing barrage of evidence, as do the perceived connections between them. Here we model scientific theories as Bayesian nets, with credences at nodes and conditional links between them modelled (...) as conditional probabilities. We update those networks, in terms of both credences at nodes and conditional probabilities at links, through a temporal barrage of random incoming evidence. Robust patterns of punctuated equilibrium, suggestive of ‘normal science’ alternating with ‘paradigm shifts,’ emerge prominently in that change dynamics. The suggestion is that at least some of the phenomena at the core of the Kuhnian tradition are predictable in the typical dynamics of scientific theory change captured as Bayesian nets under even a random evidence barrage. (shrink)

All species continuously evolve to adapt to changing environments. The genetic variation that fosters such adaptation is caused by a plethora of mechanisms, including meiotic recombination that generates novel allelic combinations in the progeny of two parental lineages. However, a considerable number of eukaryotic species, including many fungi, do not have an apparent sexual cycle and are consequently thought to be limited in their evolutionary potential. As such organisms are expected to have reduced capability to eliminate deleterious mutations, they are (...) often considered as evolutionary dead ends. However, inspired by recent reports we argue that such organisms can be as persistent as organisms with conventional sexual cycles through the use of other mechanisms, such as genomic rearrangements, to foster adaptation. (shrink)

Digital technologies are rapidly transforming economies and societies. Scholars have approached this rise of digital capitalism from various angles. However, relatively little attention has been paid to digital capitalism’s cultural underpinnings and the beliefs of those who develop most digital technologies. In this paper, we argue that a solutionist order of worth – in which value derives from solving social problems through technology – has become central to an emerging spirit of digital capitalism. We use supervised learning to trace the (...) relative importance of different orders of worth in three novel text corpora. We find that solutionism is indeed central to the normative beliefs of digital elites and the broader digital milieu, but not to capitalist discourse at large. We illustrate the importance of these findings by discussing how the spirit of digital capitalism motivates, legitimates, and orients the actions of digital capitalists. (shrink)

The standard rationality hypothesis implies that behaviour can be represented as the maximization of a suitably restricted utility function. This hypothesis lies at the heart of a large body of recent work in economics, of course, but also in political science, ethics, and other major branches of social sciences. Though the utility maximization hypothesis is venerable, it remains an area of active research. Moreover, some fundamental conceptual problems remain unresolved, or at best have resolutions that are too recent to have (...) achieved widespread understanding among social scientists. The main purpose of the Handbook of Utility Theory is to make recent developments in the area more accessible. The editors selected a number of specific topics, and invited contributions from researchers whose work had come to their attention. Therefore, the list of topics and contributions is largely the editors' responsibility. Each contributor's chapter has been refereed, and revised according to the referees' remarks. This is the first volume of a two volume set, with the second volume focusing on extensions of utility theory. (shrink)

Die vorliegenden Untersuchungen zu Aristoteles' Naturphilosophie interpretieren Haupttexte aus seinen Schriften Physik, Über Entstehen und Vergehen, Über die Entstehung der Lebewesen, Über die Seele. Sie führen zu einigen wichtigen Einsichten über die Natur, die Materie, die Zeit, die Bewegungs- und Zweckursache u.a. und erheben ihre aktuelle Bedeutung für die gegenwärtigen interdisziplinären Diskussionen zwischen Naturphilosophie, Physik, Biologie, Psychologie und Anthropologie.

Common ratio effects should be ruled out if subjects’ preferences satisfy compound independence, reduction of compound lotteries, and coalescing. In other words, at least one of these axioms should be violated in order to generate a common ratio effect. Relying on a simple experiment, we investigate which failure of these axioms is concomitant with the empirical observation of common ratio effects. We observe that compound independence and reduction of compound lotteries hold, whereas coalescing is systematically violated. This result provides support (...) for theories which explain the common ratio effect by violations of coalescing instead of violations of compound independence. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:THE CONCEPT OF PERSON IN ST. THOMAS AQUINAS: A Contribution to Recent Discussion* ST. THOMAS AQUINAS accepted and consistently defended Boethius' definition of person: "persona est substantia individua rationalis naturae." St. Thomas' analysis of this definition necessarily involves metaphysical questions because of the implications of the terms " substance" and " nature" and moreover it manifests the inescapahle imprint of the theological problematics which surrounded the issue (e.g. the (...) Trinity and the hypostatic union). Both of these influences, metaphysical and theological, have engendered problems of interpretation and criticism. Contemporary discussions of person largely either continue the scholastic controversies or adopt a modern perspective from which to expose apparent contradictions in St. Thomas' doctrine. The purpose of this article will be limited to a consideration of the metaphysical problems concerning the relationship between individual substance, universal, nature, and existence. It is hoped that such a clarification will resolve not only the neoscholastic controversies, but also some of the contemporary problems. I. BOETHIUS' DEFINITION OF PERSON AND ST. THOMAS' EXPLANATION A. BOETHIUS' DEFINITION Boethius develops his definition of person in the Liber contra Eutychen et N estorium after a careful consideration of na- * I have to thank cordially Father Brian Shanley, 0.P. for having revised completely this English version, devoting much time and energy to fit the text and the footnotes to the style of The Thomist. He adapted the version in good style and verified the Latin quotations. 435 436 HORST SEIDL ture and substance.1 In the first chapter he sets out to define nature and discovers four possible meanings. The first and broadest definition, embracing both substances and accidents, describes nature as belonging to all things which by their being can be in some way or another be comprehended by reason: "natura est earum rermn quae, cum sint, quoquo modo intellectu capi possunt." A second definition, comprising substances alone both corporeal and incorporeal, describes nature as anything that can effect or suffer something: " natura est vel quod facere vel quod pati possit." A third sense, taken from the Aristotelian analysis of the motion of natural substances, describes nature as the immanent principle of movement : "natura est motus principium per se et non per accidens." Finally, nature can also refer to the formal cause which provides the specific difference: " natura est unam quamque rem informans specifica differentia" (cf. ST Ia. 29, I ad 4). It is this last sense which is most important. In sum, "nature" is a broad term encompassing both composite beings and their causes. Boethius continues in chapter two by first narrowing the relevant sense of nature to substances (thus excluding accidents ) and then presenting a complete division of substances. The major distinction is between corporeal substances and incorporeal substances. Corporeal subdivides further into inanimate and animate, with animate dividing. into insensitive and sensitive and the latter dividing finally into irrational and rational. Incorporeal subdivides into rational and irrational (the life-principle of animals), with rational incorporeal substances being further distinguished into those that are immutable by nature (the Creator) and those that are not so by nature (the human soul and angels) but may become so by virtue of the immutable substance. Boethius then argues that person cannot be affirmed of inanimate beings or irrational animals. A 1 All citations from Boethius are taken from the Loeb text in Boethius: Theological Tractates and the Consolation of Philosophy, ed. H. F. Stewart and E. K. Rand (Cambridge: Harvard University Press, 1918). THE CONCEPT OF PERSON IN ST. THOMAS AQUINAS 437 final distinction of :substance into universal and particular leads to the conclusion that person must refer to an individual. Thus the background is set for the definition of person which opens the third chapter: " naturae rationalis individua substantia." Person must be an individual substance of a certain nature, namely rational, which nature accounts for the form or specific difference of the particular substance (the fourth meaning of chapter 1). The connection of this definition with Aristotle 's definition of man as a rational animal is unmistakable. It should also be noted that this definition of person is applicable not only to man, in whom the rational nature is not identical with his substance, but also to the... (shrink)

Die Metaphysik des Aristoteles begründete die Wissenschaft vom Seienden als Seiendes und gab der "ersten Philosophie" ihren Namen. Ausgehend vom Einzelding, das nur durch den Rückgang auf allgemeine Prinzipien erkannt werden kann, stellt Aristoteles die Lehre von den vier Ursachen auf, auf die jedes Seiende gegründet ist: Materie (causa materialis), Form (causa formalis), Bewegungsursache (causa efficiens) und Zweckursache (causa finalis). Die Metaphysik ist das grundlegende Werk der Philosophie als Wissenschaft.

Die "Metaphysik" des Aristoteles begründete die Wissenschaft vom Seienden als Seiendes und gab der 'Ersten Philosophie' ihren Namen. Ausgehend vom Einzelding, das nur durch den Rückgang auf allgemeine Prinzipien erkannt werden kann, stellt Aristoteles die Lehre von den vier Ursachen auf, auf die jedes Seiende gegründet ist: Materie , Form , Bewegungsursache und Zweckursache . Die "Metaphysik" ist das grundlegende Werk der Philosophie als Wissenschaft.

In dieser Leseausgabe werden die philosophischen Schriften von Aristoteles in der heute eingeführten Abfolge präsentiert. Als Grundlage dienten die vorhandenen Bände der Philosophischen Bibliothek, wobei auf den Abdruck des griechischen Textes verzichtet wurde. Kurze Vorbemerkungen zu den einzelnen Bänden geben eine erste Orientierung, Register erschließen die einzelnen Schriften. Die Randverweise auf die Paginierung der Gesamtausgabe der überlieferten Werke Aristoteles' von Immanuel Bekker (Berlin 1831-1870), nach der üblicherweise zitiert wird, ermöglichen ein leichtes und schnelles Auffinden gesuchter Textstellen.

Einleitende Bemerkungen zu Kunst und Kunstwerk -- Kunstphilosophische Auffassungen in kurzem -- Zur gegenwärtigen Diskussion über Kunst.

Discusses biodiversity conservation in tropical rainforests. Presents an overview of research on bioactive natural products from the Amazon. Examines current research and investigations of the chemical evolution. Addresses biogeochemistry issues of tropical systems. Provides an overview of environmental issues related to Amazon biodiversity, including the impact of surface mining on the quality of air, water, and soil.

There is a broad public interest in the current discussion about evolution and creation, a discussion led mainly by scientists on the one hand and theologians on the other. The scientists argue for the evolution of the cosmos and nature without a creator, while the theologians defend the idea of creation. However, the perspective of natural philosophy is largely missing from the debate. Since this is no longer represented in contemporary philosophical trends, this study revives it from the aristotelian-thomist tradition (...) with its valuable insights into the finality of nature, which the author uses in his attempt to mediate between scientific and theological viewpoints. (shrink)