aristotle's demonstrative logic

Demonstrative logic, the study of demonstration as opposed to persuasion, is the subject of Aristotle's two-volume Analytics. Many examples are geometrical. Demonstration produces knowledge (of the truth of propositions). Persuasion merely produces opinion. Aristotle presented a general truth-and-consequence conception of demonstration meant to apply to all demonstrations. According to him, a demonstration, which normally proves a conclusion not previously known to be true, is an extended argumentation beginning with premises known to be truths and containing a chain of reasoning showing by deductively evident steps that its conclusion is a consequence of its premises. In particular, a demonstration is a deduction whose premises are known to be true. Aristotle's general theory of demonstration required a prior general theory of deduction presented in the Prior Analytics. His general immediate-deduction-chaining conception of deduction was meant to apply to all deductions. According to him, any deduction that is not immediately evident is an extended argumentation that involves a chaining of intermediate immediately evident steps that shows its final conclusion to follow logically from its premises. To illustrate his general theory of deduction, he presented an ingeniously simple and mathematically precise special case traditionally known as the categorical syllogisti

Mapping spatial tourism and hospitality employment clusters: An application of spatial autocorrelation

This article analyzes the characteristics and spatial clustering of tourism and hospitality employment clusters in Victoria, Australia. Using cluster theory as the theoretical base, three interrelated research questions are specifically addressed: What industries constitute the tourism and hospitality sector? What broader "groupings" does the sector exhibit? Are these tourism and hospitality industries clustered around strategic areas of economic and resource advantage? Using the Australian and New Zealand Standard Industrial Classification (at the four-digit level), industries explicitly related to tourism and hospitality were first identified and total numbers of individuals working within these industries were aggregated at a level of Statistical Local Area (similar to a suburb or a neighborhood). Results show that in 2006 employment in tourism and hospitality equate to 7.74% of total employment in Australia. "Cafés and restaurants" (22%) is the single largest tourism and hospitality-related employer, followed by "takeaway food services" (20%) and "accommodation" (16%). Using factor analysis, four broader functions were extracted to characterize the underlying structure and functional interdependency among tourism and hospitality industries. These functions include: tourism operational services, hospitality services, entertainment services, and infrastructure operational facilities services. Spatial autocorrelation measures have identified five established tourism and hospitality spatial clusters in Victoria, which we argue hold the potential to act as tourism growth foci to create business synergy and generate spill-over effects through regional collaboration, competition, and sharing of pooled resources between firm

First detection of phase-dependent colliding wind X-ray emission outside the Milky Way

After having reported the detection of X-rays emitted by the peculiar system HD5980, we assess here the origin of this high-energy emission from additional X-ray observations obtained with XMM-Newton. This research provides the first detection of apparently periodic X-ray emission from hot gas produced by the collision of winds in an evolved massive binary outside the Milky Way. It also provides the first X-ray monitoring of a Luminous Blue Variable only years after its eruption and shows that the dominant source of the X-rays is not associated with the ejecta.Comment: 13 pages, 3 figures and 1 table, accepted for publication in ApJ (letters

How do people with chronically painful joint hypermobility syndrome make decisions about activity?

Background:The model of activity avoidance prompted by fear of increased pain and/or harm dominates understanding and research into activity limitation in chronic pain. Yet the accounts of people with chronic pain on decisions about activity limitation are rarely heard beyond the confines of fear and avoidance questionnaires. Methods We used semi-structured interviews to explore the decisions of 11 women attending a pain management clinic with chronically painful Joint Hypermobility Syndrome (JHS). Results Six themes emerged from Interpretative Phenomenological Analysis: the overall aim of keeping pain to a manageable level; considering whether the planned activity was worth it; and running through all judgements, the influence of pain intensity. The decision was tipped towards avoidance by unpredictability of pain and by high emotional cost and towards going ahead with the activity by the wish to exert control and by low emotional cost. Many accounts described a specifiable cost-benefit analysis of individual decisions, weighing the importance of each activity against its potential aversive consequences, which only in a minority of cases was dominated by fear of pain or injury. Conclusions Assumptions of fear as the basis of activity avoidance should not be used uncritically in clinical settings. Decisions about activity should explore beyond pain expectancy, incorporating goals, values, and decision processes