Nucleation and motion of kink pairs on partial dislocations are examined by elasticity theory for materials with a high Peierls stress. Two approaches are used: one considers the change in average stacking-fault energy due to alloying elements and the other considers the change in local SFE due to a nearby solute atom. Both approaches highlight the role of SFE on kink nucleation, propagation and annihilation and both furnish strain rate as a function of stress, temperature and SFE. Model predictions are (...) compared with yield stress data for two systems: firstly, an intermetallic, MoSi 2 , which softens for alloying elements that decrease the SFE and hardens for Re additions that increase the SFE; secondly, a ceramic oxide, MgO-Al 2 O 3 spinel, which softens with increasing addition of excess alumina and at the same time exhibits a decrease in SFE. The average SFE approach agrees qualitatively with the data while quantitative agreement is obtained with the local SFE approach. The possibility is considered that the model applies to other materials, such as TiAl, HfV 2 and Fe 3 Al, which show softening with certain alloying additions. One requirement is that the dislocations are dissociated more than a few atomic distances; otherwise kink nucleation occurs on the perfect dislocation . Hence the model does not apply to materials such as bcc metals which only have a core dissociation. Normal hardening effects of solutes from size and modulus misfits are additive with any softening effects from a decrease in SFE and so may mask the latter, as occurs for W additions to MoSi 2. (shrink)

An alleged moral right to informational privacy assumes that we should have control over information about ourselves. What is the philosophical justification for this control? I think that one prevalent answer to this question—an answer that has to do with the justification of negative rights generally—will not do.

Mr Olding's recent attack on my exposition of the argument from design gives me an opportunity to defend the central theses of my original article. My article pointed out that there were arguments from design of two types—those which take as their premisses regularities of copresence and those which take as their premisses regularities of succession. I sought to defend an argument of the second type. One merit of such an argument is that there is no doubt about the truth (...) of its premisses. Almost all objects in the world behave in a highly regular way describable by scientific laws. Further, any scientific explanation of such a regularity must invoke some more general regularity. The most general regularities of all are, as such, scientifically inexplicable. The question arises whether there is a possible explanation of another kind which can be provided for them, and whether their occurrence gives any or much support to that explanation. I urged that we do explain some phenomena by explanation of an entirely different kind from the scientific. We explain states of affairs by the action of agents who bring them about intentionally of their own choice. Regularities of succession, as well as other phenomena may be explained in this way. Explanation of this kind I will term intentional explanation. Intentional explanation of some phenomenon E consists in adducing an agent A who brought E about of his own choice and a further end G which, he believed, would be forwarded by the production of E. (shrink)

On what grounds will the rational man become a Christian? It is often assumed by many, especially non-Christians, that he will become a Christian if and only if he judges that the evidence available to him shows that it is more likely than not that the Christian theological system is true, that, in mathematical terms, on the evidence available to him, the probability of its truth is greater than half. It is the purpose of this paper to investigate whether or (...) not this is a necessary and sufficient condition for the rational man to adopt Christianity. (shrink)

In this article we show that it is possible to completely classify the degrees of r.e. bases of r.e. vector spaces in terms of weak truth table degrees. The ideas extend to classify the degrees of complements and splittings. Several ramifications of the classification are discussed, together with an analysis of the structure of the degrees of pairs of r.e. summands of r.e. spaces.

This treatise on aesthetics criticizes various psychological theories of art, offers new theories and interpretations, and draws important inferences concerning ...

Published posthumously in 1964, this volume contains a fantastic collection of essays by R. G. Collingwood on the subject of art and it's relationship with philosophy. Robin George Collingwood, FBA (1889 - 1943) was an English historian, philosopher, and archaeologist most famous for his philosophical works including "The Principles of Art" (1938) and the posthumously-published "The Idea of History" (1946). This fascinating volume will appeal to those with an interest in Collingwood's seminal work, and is not to be missed by (...) students of philosophy and art. Contents include: "Ruskin not a Philosophical Writer," "Ruskin's Attitude towards Philosophy," "On the Philosophy of Non-Philosophers," "Logicism and Historicism," "Ruskin as Historicist," "The Anti-Historicism of Ruskin's Contemporaries," "The Unity of the Spirit: Corollaries and Illustrations," "Ruskin and Browning," etc. Many vintage books such as this are increasingly scarce and expensive. It is with this in mind that we are republishing this volume today in an affordable, modern edition complete with a specially-commissioned new biography of the author. (shrink)

In Ethics and the Limits of Philosophy, Bernard Williams is rather severe on what he thinks of as an ethics of obligation. He has in mind by this Kant and W. D. Ross. For many, obligation seems the very core of ethics and the moral realm, and lives more generally are seen through the prism of this notion. This, according to Williams, flattens out our lives and moral experience and fails to take into account things which are obviously important to (...) our lives. Once we take these things into account, what do we do if they come into conflict with some of our moral obligations, as Williams, in his earlier writings on moral luck, thought to be the case. I want here to explore some of these ideas, in a way that I think harmonious with Williams's general bent though not one that I intend as in any way detailed exegesis of Williams's work. (shrink)

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)