By considering the irreducible representations of the Lorentz group, an analysis of the different spin-2 waves is presented. In particular, the question of the helicity is discussed. It is concluded that, although from the point of view of representation theory there are no compelling reasons to choose between spin-2 waves with helicity σ=±1 or σ=±2, consistency arguments of the ensuing field theories favor waves with helicity σ=±1.

A critical review of gravitational wave theory is made. It is pointed out that the usual linear approach to the gravitational wave theory is neither conceptually consistent nor mathematically justified. Relying upon that analysis it is argued that—analogously to a Yang-Mills propagating field, which must be nonlinear to carry its gauge charge—a gravitational wave must necessarily be nonlinear to transport its own charge—that is, energy-momentum.

This paper examines the strengths and weaknesses of one of science's most pervasive and flexible metaprinciples;optimalityis used to explain utility maximization in economics, least effort principles in physics, entropy in chemistry, and survival of the fittest in biology. Fermat's principle of least time involves both teleological and causal considerations, two distinct modes of explanation resting on poorly understood psychological primitives. The rationality heuristic in economics provides an example from social science of the potential biases arising from the extreme flexibility of (...) optimality considerations, including selective search for confirming vidence, ex post rationalization, and the confusion of prediction with explanation. Commentators are asked to reflect on the extent to which optimality is an organizing principle of nature, a set of relatively unconnected techniques of science, a normative principle for rational choice and social organization, a metaphysical way of looking at the world, or something else still. (shrink)

From the 5th edition of Beauchamp and Childress' Principles of Biomedical Ethics, the problem of common morality has been given a more prominent role and emphasis. With the publication of the 6th and latest edition, the authors not only attempt to ground their theory in common morality, but there is also an increased tendency to identify the former with the latter. While this stratagem may give the impression of a more robust, and hence stable, foundation for their theoretical construct, we (...) fear that it comes with a cost, namely the need to keep any theory in medical ethics open to, and thereby aware of, the challenges arising from biomedical research and clinical practice, as well as healthcare systems. By too readily identifying the moral life of common morality with rule-following behaviour, Beauchamp and Childress may even be wrong about the nature of common morality as such, thereby founding their, by now, classic theory on quicksand instead of solid rock. (shrink)

Truth and Meaning is a classic collection of original essays on fundamental questions in the philosophy of language. It was first published in 1976, and has remained essential reading in this area ever since. The contributors include leading figures in late twentieth-century philosophy, such as Donald Davidson, Saul Kripke, P. F. Strawson, and Michael Dummett.

This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain (...) in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant. (shrink)

This paper critically examines the predominant arguments that have been proposed either in favour or against non-benefit medical research with human subjects incapable of informed consent. It is argued that none of the arguments succeeds, while acknowledging that such research is necessary.

How should we assess the appeal of multiple scientific theories when they can all explain a particular empirical phenomenon of interest? We contrast Huygens' and Fermat's explanations of the law of refraction of light and find that neither dominates the other when considering multiple criteria for assessing the overall appeal of a scientific theory. The absence of teleology in Huygens' account is a strong plus compared to Fermat's. But Huygens' wave theory scores less well with respect to other desiderata for (...) a scientific theory. In this case, there does not appear to be a clear winner, nor need there be one. (shrink)