The theory of mental models and its computer implementations have led to crucial experiments showing that no standard logic—the sentential calculus and all logics that include it—can underlie human reasoning. The theory replaces the logical concept of validity (the conclusion is true in all cases in which the premises are true) with necessity (conclusions describe no more than possibilities to which the premises refer). Many inferences are both necessary and valid. But experiments show that individuals make necessary inferences that are (...) invalid, e.g., Few people ate steak or sole; therefore, few people ate steak. Other crucial experiments show that individuals reject inferences that are not necessary but valid, e.g., He had the anesthetic or felt pain, but not both; therefore, he had the anesthetic or felt pain, or both. Nothing in logic can justify the rejection of a valid inference: a denial of its conclusion is inconsistent with its premises, and inconsistencies yield valid inferences of any conclusions whatsoever including the one denied. So inconsistencies are catastrophic in logic. In contrast, the model theory treats all inferences as defeasible (nonmonotonic), and inconsistencies have the null model, which yields only the null model in conjunction with any other premises. So inconsistences are local. Which allows truth values in natural languages to be much richer than those that occur in the semantics of standard logics; and individuals verify assertions on the basis of both facts and possibilities that did not occur. (shrink)

What makes the words we speak mean what they do? Possible-worlds semantics articulates the view that the meanings of words contribute to determining, for each sentence, which possible worlds would make the sentence true, and which would make it false. M. J. Cresswell argues that the non-semantic facts on which such semantic facts supervene are facts about the causal interactions between the linguistic behaviour of speakers and the facts in the world that they are speaking about, and that the kind (...) of causation involved is best analysed using David Lewis's account of causation in terms of counterfactuals. Although philosophers have worked on the question of the connection between meaning and linguistic behaviour, it has mostly been without regard to the work done in possible-world semantics and Language in the World is a book-length examination of this problem. (shrink)

Abstract: Retama raetam (RR) is a traditional medicinal plant belongs to fabaceae family which grows in North Africa and East Mediterranean region. Locally, RR is used in several diseases including diabetes mellitus and hypertension. Thus, this study aims to investigate certain behavioral and central effects of methanolic extract of RR seeds in experimental animals (male Albino adult mice of 20 – 35 gm). Three exploratory behavioral models are used in this study, open field, elevated plus maze and light-dark box models, (...) in addition, picrotoxin induced seizure model in mice. In elevated plus-maze test of anxiety, a dose of 25 mg/kg of RR induced a significant increase in number of open arms entries and time spent on open arms of the maze compared to the control. In light-dark model, time spent on light area and number of light-dark transitions are significantly increased after treatment with 25 mg/kg RR extract of seeds. Open field model also revealed a significant increase in general motor activity of the mouse after 25 mg/kg of RR. On the other hand, a dose of 50 mg/kg of RR significantly induced a profound central and peripheral analgesic responses. In summary, this study concludes that RR seeds have a profound anxiolytic-like effect and analgesic response with delay in latency time of seizure induced by picrotoxin in mice. (shrink)

When people understand a counterfactual such as “if the flowers had been roses, the trees would have been orange trees,” they think about the conjecture, “there were roses and orange trees,” and they also think about its opposite, the presupposed facts. We test whether people think about the opposite by representing alternates, for example, “poppies and apple trees,” or whether models can contain symbols, for example, “no roses and no orange trees.” We report the discovery of an inference‐to‐alternates effect—a tendency (...) to make an affirmative inference that refers to an alternate even from a negative minor premise, for example, “there were no orange trees, therefore there were poppies.” Nine experiments show the inference‐to‐alternates effect occurs in a binary context, but not a multiple context, and for direct and indirect reference; it can be induced and reduced by prior experience with similar inferences, and it also occurs for indicative conditionals. The results have implications for theories of counterfactual conditionals, and of negation. (shrink)

We consider the desirability, or otherwise, of various forms of induction in the light of certain principles and inductive methods within predicate uncertain reasoning. Our general conclusion is that there remain conflicts within the area whose resolution will require a deeper understanding of the fundamental relationship between individuals and properties.

Morgan has argued that attitudes to the medicalisation of sports are historically conditioned.While the history of doping offers contested versions of when the sports world turned againstconservative forces, Morgan has argued that these attitudes are out of step with prevailingnorms and that the World Anti Doping Agency's policy needs to be modified to better reflectthis. As an advocate of critical democracies in sports, he argues that anti-doping policy mustacknowledge and reflect these shifts in order to secure their legitimacy. In response, (...) wecritically present the World Anti-Doping Agency's policy that incorporates the Prohibited Listof Substances and Methods for athletes. We evaluate the validity of the therapy-enhancementdistinction in relation to its role in both justifying and sustaining the operation of theProhibited List. In particular, we focus on the case of thyroxine, which has been the subjectof controversy in athletic doping. While thyroxine is not currently banned, critics haveclaimed that its use in the absence of a relevant pathology is tantamount to doping. Wechallenge Morgan's claim that a conventionalist defence of the therapy-enhancementdistinction is the best available, and his conclusion that this properly supports a morepermissive stance towards performance-enhancing drug use. Furthermore, we reject hisconventionalist support for democratic line drawing in relation to doping and in particular thestatus of thyroxine with regard to the prohibited list. We offer a modified defence of the statusquo, a qualified, naturalist account of health and disease, where athletes may be prescribeddrugs that are genuine responses to medical necessity that do not, or do not typically, threatenthe goods of athletic excellence. (shrink)

Rudolf Bultmann was one of the leading thinkers within an influential theological direction that arose in Europe after the First World War, known as dialectical theology. Comprehensive introductions to the life and work of Bultmann in the South African theological journals, written in Afrikaans, either does not exist, or are difficult to trace for the Afrikaans readership. This article on Bultmann aims to fill the gap by offering a lexicographical contribution on the life and work of Bultmann. The focus of (...) this article is on Bultmann as a Lutheran thinker. The theme of the New Testament and systematic theology is essentially the same, namely to explain the concept of Christian self-understanding as an eschatological event in which faith is expressed for the sake of faith in God and only in God. Bultmann explained the same theological concepts with his theology as those that were explained by the church reformers of the 16th century, but under radically new circumstances. The so-called modern and postmodern people of our time not only broke ties with the past, but in the process they also lost their ability for using historical-critical patterns of thought that tries to bridge historical distances, and therefore sacrificed all efforts to think systematically on the altar of relativism. We can learn from Bultmann what systematic reformed theology really is. (shrink)