It is shown that the Riemannian curvature of the 3-dimensional hypersurfaces in space-time, described by the Wilson loop integral, can be represented by a quaternion quantum operator induced by the SU(2) gauge potential, thus providing a justification for quaternion quantum gravity at the Tev energy scale.

BackgroundThe outbreak of novel coronavirus disease 2019 has caused a global panic and public concern due to its mortality ratio and lack of treatments/vaccines. Reduced levels of physical activity have been reported during the outbreak, affecting the normal daily pattern.ObjectiveTo investigate the relationship of physical activity level with sleep quality and the effects of reduction physical activity levels on sleep quality.MethodsA Google form was used to address personal information, COVID-19 personal care, physical activity, and mental health of 1,907 adult volunteers. (...) Binary logistic regression was used to verify the association of physical activity parameters and sleep quality.ResultsInsufficient physical activity levels were a risk factor to have disturbed sleep pattern [OR: 1.28, 95% CI ]; however, when the BMI was added to the analysis, there was no more statistical difference [OR: 1.23, 95% CI ]. On the other hand, we found that the reduction of physical activity levels was associated with negative changes in sleep quality [OR: 1.73, 95% CI ], regardless all the confounders [OR: 1.30, 95% CI ], unless when feeling of depression was added in Model 6 [OR: 1.28, 95% CI ].ConclusionDisruption in daily physical activity routine, rather than physical activity level, negatively influences sleep quality during the COVID-19 quarantine. (shrink)

The central insight of Darwin's Origin of Species is that evolution is an ecological phenomenon, arising from the activities of organisms in the 'struggle for life'. By contrast, the Modern Synthesis theory of evolution, which rose to prominence in the twentieth century, presents evolution as a fundamentally molecular phenomenon, occurring in populations of sub-organismal entities - genes. After nearly a century of success, the Modern Synthesis theory is now being challenged by empirical advances in the study of organismal development and (...) inheritance. In this important study, D. M. Walsh shows that the principal defect of the Modern Synthesis resides in its rejection of Darwin's organismal perspective, and argues for 'situated Darwinism': an alternative, organism-centred conception of evolution that prioritises organisms as adaptive agents. His book will be of interest to scholars and advanced students of evolutionary biology and the philosophy of biology. (shrink)

According to historical theories of biological function, a trait's function is determined by natural selection in the past. I argue that, in addition to historical functions, ahistorical functions ought to be recognized. I propose a theory of biological function which accommodates both. The function of a trait is the way it contributes to fitness and fitness can only be determined relative to a selective regime. Therefore, the function of a trait can only be specified relative to a selective regime. Apart (...) from its desirable pluralism, only this view of relational function can support the function/accident and function/malfunction distinctions commonly thought to be part of the concept of function. Furthermore, only relational function correctly characterizes the explanatory consequences of function attributions in evolutionary biology. (shrink)

Breaking new ground in the debate about the relation of mind and body, David Armstrong's classic text - first published in 1968 - remains the most compelling and comprehensive statement of the view that the mind is material or physical. In the preface to this new edition, the author reflects on the book's impact and considers it in the light of subsequent developments. He also provides a bibliography of all the key writings to have appeared in the materialist debate.

In this important study D. M. Armstrong offers a comprehensive system of analytical metaphysics that synthesises but also develops his thinking over the last twenty years. Armstrong's analysis, which acknowledges the 'logical atomism' of Russell and Wittgenstein, makes facts the fundamental constituents of the world, examining properties, relations, numbers, classes, possibility and necessity, dispositions, causes and laws. All these, it is argued, find their place and can be understood inside a scheme of states of affairs. This is a comprehensive and (...) rigorously this-worldly account of the most general features of reality, argued from a distinctive philosophical perspective, and it will appeal to a wide readership in analytical philosophy. (shrink)

Evolutionary Biology has two principal explananda, fit and diversity (Lewontin 1978). Natural selection theory stakes its claim to being the central unifying concept in biology on the grounds that it demonstrates both phenomena to be the consequence of a single process. By now the standard story hardly needs reiterating: Natural selection is a force that operates over a population, preserving the better fit, culling the less fit, and along the way promoting novel solutions to adaptive problems. Amundson’s historical survey of (...) the concept of adaptation captures the idea succinctly: The phenomenon of adaptation is at the core of modern evolutionary biology. Natural selection, the mechanism universally regarded as the primary causal influence on phenotypic evolutionary change, is first and foremost an explanation of adaptation. (1996: 11) At the same time, it appears that the capacity of natural selection to cause adaptations cannot account for every feature of the nature and distribution of biological form. Reason to believe this devolves from the simple fact that the bearers of biological form are organisms and a salient fact about organisms is that each faces the tribunal of the environment as a corporate entity, not as a loose aggregate of independent traits. One consequence of this fact is that at each stage of its development from egg to adult an organism must be an integrated, functioning whole. Another is that for any form to arise in an organism at a time, it must develop from the materials and processes at the organism’s disposal. The requirement of integration and the processes of development that produce it leave their distinctive marks on form. It seems reasonable, then, to suppose that one might appeal to the processes of development and the principles by which they operate in explaining the nature and distribution of biological form. (See here Gould 1977; Rose and Lauder 1996). (shrink)

Truths are determined not by what we believe, but by the way the world is. Or so realists about truth believe. Philosophers call such theories correspondence theories of truth. Truthmaking theory, which now has many adherents among contemporary philosophers, is the most recent development of a realist theory of truth, and in this book D. M. Armstrong offers the first full-length study of this theory. He examines its applications to different sorts of truth, including contingent truths, modal truths, truths about (...) the past and the future, and mathematical truths. In a clear, even-handed and non-technical discussion he makes a compelling case for truthmaking and its importance in philosophy. His book marks a significant contribution to the debate and will be of interest to a wide range of readers working in analytical philosophy. (shrink)

A wide-ranging study of the central concepts in epistemology - belief, truth and knowledge. Professor Armstrong offers a dispositional account of general beliefs and of knowledge of general propositions. Belief about particular matters of fact are described as structures in the mind of the believer which represent or 'map' reality, while general beliefs are dispositions to extend the 'map' or introduce casual relations between portions of the map according to general rules. 'Knowledge' denotes the reliability of such beliefs as representations (...) of reality. Within this framework Professor Armstrong offers a distinctive account of many of the main questions in general epistemology - the relations between beliefs and language, the notions of proposition, concept and idea, the analysis of truth, the varieties of knowledge, and the way in which beleifs and knowledge are supported by reasons. The book as a whole if offered as a contribution to a naturalistic account of man. (shrink)

The most compelling extant accounts of explanation casts all explanations as causal. Yet there are sciences, theoretical population biology in particular, that explain their phenomena by appeal to statistical, non-causal properties of ensembles. I develop a generalised account of explanation. An explanation serves two functions: metaphysical and cognitive. The metaphysical function is discharged by identifying a counterfactually robust invariance relation between explanans event and explanandum. The cognitive function is discharged by providing an appropriate description of this relation. I offer examples (...) of explanations from portfolio theory and population genetics that meet this characterisation. In each case the invariance relation holds between a statistical property of an ensemble and a change in structure of the ensemble. In neither case, however, does the statistical property cause the outcome it explains. There are genuine statistical, non-causal scientific explanations. (shrink)

This is a study of a crucial and controversial topic in metaphysics and the philosophy of science: the status of the laws of nature. D. M. Armstrong works out clearly and in comprehensive detail a largely original view that laws are relations between properties or universals. The theory is continuous with the views on universals and more generally with the scientific realism that Professor Armstrong has advanced in earlier publications. He begins here by mounting an attack on the orthodox and (...) sceptical view deriving from Hume that laws assert no more than a regularity of coincidence between instances of properties. In doing so he presents what may become the definitive statement of the case against this position. Professor Armstrong then goes on to establish his own theory in a systematic manner defending it against the most likely objections, and extending both it and the related theory of universals to cover functional and statistical laws. This treatment of the subject is refreshingly concise and vivid: it will both stimulate vigorous professional debate and make an excellent student text. (shrink)

In this short text, a distinguished philosopher turns his attention to one of the oldest and most fundamental philosophical problems of all: How it is that we are able to sort and classify different things as being of the same natural class? Professor Armstrong carefully sets out six major theories—ancient, modern, and contemporary—and assesses the strengths and weaknesses of each. Recognizing that there are no final victories or defeats in metaphysics, Armstrong nonetheless defends a traditional account of universals as the (...) most satisfactory theory we have.This study is written for advanced students, but as Armstrong goes considerably beyond his earlier work on this topic, it will interest professional scholars as well. Carefully plotted and clearly written, Universals is both a paradigm of exposition and a case study on the value of careful analysis of fundamental issues in philosophy. (shrink)

Dispositions are essential to our understanding of the world. IDispositions: A Debate is an extended dialogue between three distinguished philosophers - D.M. Armstrong, C.B. Martin and U.T. Place - on the many problems associated with dispositions, which reveals their own distinctive accounts of the nature of dispositions. These are then linked to other issues such as the nature of mind, matter, universals, existence, laws of nature and causation.

This is a study, in two volumes, of one of the longest-standing philosophical problems: the problem of universals. In volume I David Armstrong surveys and criticizes the main approaches and solutions to the problems that have been canvassed, rejecting the various forms of nominalism and 'Platonic' realism. In volume II he develops an important theory of his own, an objective theory of universals based not on linguistic conventions, but on the actual and potential findings of natural science. He thus reconciles (...) a realism about qualities and relations with an empiricist epistemology. The theory allows, too, for a convincing explanation of natural laws as relations between these universals. (shrink)

A. D. M. Walker; III*—Gratefulness and Gratitude, Proceedings of the Aristotelian Society, Volume 81, Issue 1, 1 June 1981, Pages 39–56, https://doi.org/10.1093.

This is a collection of twenty-five papers and reviews by the leading analytic philosopher of our time. It adds to the papers on metaphysics and epistemology to be found in his previous two-volume collection published by Oxford University Press. One previously unpublished paper—“Why Conditionalize?”—is included. Australasian philosophers may note with some pride that eleven of the pieces were first published in the Australasian Journal of Philosophy.

This is a study, in two volumes, of one of the longest-standing philosophical problems: the problem of universals. In volume I David Armstrong surveys and criticizes the main approaches and solutions to the problems that have been canvassed, rejecting the various forms of nominalism and 'Platonic' realism. In volume II he develops an important theory of his own, an objective theory of universals based not on linguistic conventions, but on the actual and potential findings of natural science. He thus reconciles (...) a realism about qualities and relations with an empiricist epistemology. The theory allows, too, for a convincing explanation of natural laws as relations between these universals. (shrink)