An in-situ transmission electron microscopy straining technique has been used to investigate the dynamics of dislocation-defect interactions in ion-irradiated copper and the subsequent formation of defect-free channels. Defect removal frequently required interaction with multiple dislocations, although screw dislocations were more efficient at annihilating defects than edge dislocations were. The defect pinning strength was determined from the dislocation curvature prior to breakaway and exhibited values ranging from 15 to 175 MPa. Pre-existing dislocations percolated through the defect field but did not show (...) long-range motion, indicating that they are not responsible for creating the defect-free channels and have a limited contribution to the total plasticity. Defect-free channels were associated with the movement of many dislocations, which originated from grain boundaries or regions of high stress concentration such as at a crack tip. These experimental results are compared with atomistic simulations of the interaction of partial dislocations with defects in copper and a dispersed-barrier-hardening crystal plasticity model to correlate the observations to bulk mechanical properties. (shrink)

Cover -- Half Title -- Title Page -- Copyright Page -- Original Copyright Page -- Dedication -- Table of Contents -- INTRODUCTION -- VOLTAIRE -- HUME -- ROBERTSON -- GIBBON -- INDEX.

According to probabilistic theories of reasoning in psychology, people's degree of belief in an indicative conditional `if A, then B' is given by the conditional probability, P(B|A). The role of language pragmatics is relatively unexplored in the new probabilistic paradigm. We investigated how consequent relevance a ects participants' degrees of belief in conditionals about a randomly chosen card. The set of events referred to by the consequent was either a strict superset or a strict subset of the set of events (...) referred to by the antecedent. We manipulated whether the superset was expressed using a disjunction or a hypernym. We also manipulated the source of the dependency, whether in long-term memory or in the stimulus. For subset-consequent conditionals, patterns of responses were mostly conditional probability followed by conjunction. For superset-consequent conditionals, conditional probability responses were most common for hypernym dependencies and least common for disjunction dependencies, which were replaced with responses indicating inferred consequent irrelevance. Conditional probability responses were also more common for knowledge-based than stimulus-based dependencies. We suggest. (shrink)

This collection by some of the leading scholars of Strauss's work is the first devoted to Strauss's thought regarding education. It seeks to address his conception of education as it applies to a range of his most important concepts, such as his views on the importance of revelation, his critique of modern democracy and the importance of modern classical education.

We investigated how people interpret conditionals and how stable their interpretation is over a long series of trials. Participants were shown the colored patterns on each side of a six-sided die, and were asked how sure they were that a conditional holds of the side landing upwards when the die is randomly thrown. Participants were presented with 71 trials consisting of all combinations of binary dimensions of shape (e.g., circles and squares) and color (e.g., blue and red) painted onto the (...) sides of each die. In two experiments (N1 = 66, N2 = 65), the conditional event was the dominant interpretation, followed by conjunction, and material conditional responses were negligible. In both experiments, the percentage of participants giving a conditional event response increased from around 40% at the beginning of the task to nearly 80% at the end, with most participants shifting from a conjunction interpretation. The shift was moderated by the order of shape and color in each conditional’s antecedent and consequent: participants were more likely to shift if the antecedent referred to a color. In Experiment 2 we collected response times: conditional event interpretations took longer to process than conjunction interpretations (mean difference 500 ms). We discuss implications of our results for mental models theory and probabilistic theories of reasoning. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:69 WILLIAM ROBERTSON AND DAVID HUME: THREE LETTERS The relationship between David Hume and his fellow Scottish historian William Robertson has always seemed one-sided. Despite the existence of fifteen letters to Robertson in the standard volumes of Hume's correspondence,1 Hume scholars have long had reason to regret the lack of a single extant letter from Robertson to Hume. None are to be found, for example, (...) where one would most expect them to be — in the Royal Society of Edinburgh, alongside the letters to Hume from various other Moderate clergymen and literati in Robertson's circle, such as Hugh Blair and Adam Ferguson. Fortunately, however, two of Robertson's letters to Hume (numbered II and III below) have now turned up where one would not expect them to be — among Robertson's own correspondence in the Robertson2 Macdonald Papers, National Library of Scotland. They are not mere drafts, such as one is accustomed to find among an author's private papers; rather, they are autograph signed letters that appear to have actually been posted. How and when they found their way back to Robertson's personal papers, and what became of the rest of Robertson's letters to Hume, are questions open to speculation. For the moment we are grateful for the letters we now have, neither of which is known to have been published before in whole or in part. Nor has Hume been identified before as the recipient of either of these letters, though internal evidence makes it clear that he was. Both letters date from the late 1760s, when Hume was living in London and Robertson was at the peak of his multi-faceted career in Edinburgh as university principal, parish minister, ecclesiastical leader, and man of letters. The first of them, dated 27 March 1767, was sent to Hume in his capacity as under- 70 secretary of state in the Northern Department (an office he held from February 1767 to January 1768). It is plainly a reply to a letter of 19 March, in which Hume had discussed three topics to which Robertson was 5 responding: Robertson's efforts to secure a military chaplaincy for a certain Scottish minister (evidently named Brodie); Conway's role in the famous dispute between Hume and Rousseau; and the public response to Adam Ferguson's newly published Essay on the History of Civil Society. In addition Robertson addresses a matter that Hume had apparently broached with him at some earlier time: the attempt to find a suitable Scottish church to which Hume might obtain a crown presentation for his nephews' tutor, the Rev. Christopher Tait. The letter concludes on a note of admiration that is characteristic not only of Robertson but of most of Hume's other "Protestant Pastors" in Scotland. The second letter to Hume, dated 31 January 1769, is chiefly concerned with the forthcoming publication of Robertson's History of Charles V and the French translation of it by J.-B.-A. Suard — subjects that had been treated in two letters from Hume to 7 Robertson of autumn 1768. It also contains a strong recommendation for a bright young Scottish writer (in both the legal and literary senses of that term) who would one day become Robertson's most vitriolic critic: Gilbert Stuart. On the personal side, there is encouragement for the now unemployed Hume to return to Edinburgh, as he was then threatening to do, after his "great glut of society" at Paris and London, and there are allusions in the closing paragraph to Hume's part in introducing his friend to polite society when Robertson had visited London to arrange the publication of Charles V in the spring of 1768. 71 To these two letters from Robertson we have prefixed a third from earlier in the same decade, one Q not actually addressed to Hume but largely about him. Robertson wrote it to their common friend Gilbert Elliot (later Sir Gilbert Elliot) on 8 March 1762, two days before the Town Council elected Robertson principal of Edinburgh University. The first paragraph deals with the principalship and relates to Hume only indirectly, as we point out in a footnote. The second paragraph, however, contains interesting... (shrink)

Conditionals are central to inference. Before people can draw inferences about a natural language conditional, they must interpret its meaning. We investigated interpretation of uncertain conditionals using a probabilistic truth table task, focussing on (i) conditional event, (ii) material conditional, and (iii) conjunction interpretations. The order of object (shape) and feature (color) in each conditional's antecedent and consequent was varied between participants. The conditional event was the dominant interpretation, followed by conjunction, and took longer to process than conjunction (mean di (...) erence 500 ms). Material conditional responses were rare. The proportion of conditional event responses increased from around 40% at the beginning of the task to nearly 80% at the end, with 55% of participants showing a qualitative shift of interpretation. Shifts to the conditional event occurred later in the feature-object order than in the object-feature order. We discuss the results in terms of insight and suggest implications for theories of interpretation. (shrink)

Reasoning under uncertainty, that is, making judgements with only partial knowledge, is a major theme in artificial intelligence. Professor Paris provides here an introduction to the mathematical foundations of the subject. It is suited for readers with some knowledge of undergraduate mathematics but is otherwise self-contained, collecting together the key results on the subject, and formalising within a unified framework the main contemporary approaches and assumptions. The author has concentrated on giving clear mathematical formulations, analyses, justifications and consequences of the (...) main theories about uncertain reasoning, so the book can serve as a textbook for beginners or as a starting point for further basic research into the subject. It will be welcomed by graduate students and research workers in logic, philosophy, and computer science as a textbook for beginners, a starting point for further basic research into the subject, and not least, an account of how mathematics and artificial intelligence can complement and enrich each other. (shrink)

We present six significant open problems in Pure Inductive Logic, together with their background and current status, with the intention of raising awareness and leading ultimately to their resolution.

Context. The identification of the sources that reionized the Universe and their specific contribution to this process are key missing pieces of our knowledge of the early Universe. Faint star-forming galaxies may be the main contributors to the ionizing photon budget during the epoch of reionization, but their escaping photons cannot be detected directly due to inter-galactic medium opacity. Hence, it is essential to characterize the properties of faint galaxies with significant Lyman continuum photon leakage up to z 4 to (...) define indirect indicators allowing analogues to be found at the highest redshift. Aims. Long gamma-ray bursts explode typically in star-forming regions of faint, star-forming galaxies. Through LGRB afterglow spectroscopy it is possible to detect directly LyC photons. Our aim is to use LGRBs as tools to study LyC leakage from faint, star-forming galaxies at high redshift. Methods. Here we present the observations of LyC emission in the afterglow spectra of GRB 191004B at z = 3:5055, together with those of the other two previously known LyC-emitting LGRB, to determine their LyC escape fraction and compare their properties. Results. From the afterglow spectrum of GRB 191004B we determine a neutral hydrogen column density at the LGRB redshift of og =17:2 0:15, and negligible extinction. The only metal absorption lines detected are C iv and Si iv. In contrast to GRB 050908 and GRB 060607A, the host galaxy of GRB 191004B displays significant Ly emission. From its Ly emission and the non-detection of Balmer emission lines we constrain its star-formation rate to 1 SFR 4:7 M yr. 1. We fit the Ly emission with a shell model and find parameters values consistent with the observed ones. The absolute LyC escape fractions we find for GRB 191004B, GRB 050908 and GRB 060607A are of 0:35+0:10.0:11, 0:08+0:05.0:04 and :20+0:05.0:05, respectively. We compare the LyC escape fraction of LGRBs to the values of other LyC emitters found from the literature, showing that LGRB afterglows can be powerful tools to study LyC escape for faint high-redshift star-forming galaxies. Indeed we could push LyC leakage studies to much higher absolute magnitudes. The host galaxies of the three LGRB presented here have all M1600 >.19:5 mag, with the GRB 060607A host at M1600 >.16 mag. LGRB hosts may therefore be particularly suitable for exploring the ionizing escape fraction in galaxies that are too faint or distant for conventional techniques. Furthermore the time investment is very small compared to galaxy studies. (shrink)

J. B. Schneewind's "The Invention of Autonomy" has been hailed as a major interpretation of modern moral thought. Schneewind's narrative, however, elides several serious interpretive issues, particularly in the transition from late medieval to early modern thought. This results in potentially distorted accounts of Thomas Aquinas, Hugo Grotius, and G. W. Leibniz. Since these thinkers play a crucial role in Schneewind's argument, uncertainty over their work calls into question at least some of Schneewind's larger agenda for the history of ethics.

In his 1974 paper “Popper’s qualitative theory of verisimilitude” published in the British Journal for the Philosophy of Science David Miller gave his so called ‘Weather Example’ to argue that the Hamming distance between constituents is flawed as a measure of proximity to truth since the former is not, unlike the latter, translation invariant. In this present paper we generalise David Miller’s Weather Example in both the unary and polyadic cases, characterising precisely which permutations of constituents/atoms can be effected by (...) translations. In turn this suggests a meta-principle of the rational assignment of subjective probabilities, that rational principles should be preserved under translations, which we formalise and give a particular characterisation of in the context of Unary Pure Inductive Logic. (shrink)