Sex differences in reproductive strategy and the sexual division of labor resulted in selection for and maintenance of sexual dimorphism across a wide range of characteristics, including body size, hormonal physiology, behavior, and perhaps spatial abilities. In laboratory tasks among undergraduates there is a general male advantage for navigational and mental-rotation tasks, whereas studies find female advantage for remembering item locations in complex arrays and the locations of plant foods. Adaptive explanations of sex differences in these spatial abilities have focused (...) on patterns of differential mate search and routine participation in distinct subsistence behaviors. The few studies to date of spatial ability in nonindustrial populations practicing subsistence lifestyles, or across a wider age range, find inconsistent results. Here we examine sex- and age-based variation in one kind of spatial ability related to navigation, dead-reckoning, among Tsimane forager horticulturalists living in lowland Bolivia. Seventy-three participants (38 male) aged 6–82 years pointed a handheld global positioning system (GPS) unit toward the two nearest communities and the more distant market town. We find no evidence of sex differences in dead reckoning (p = 0.47), nor do we find any evidence of age-related decline in dead-reckoning accuracy (p = 0.28). Participants were significantly more accurate at pointing toward the market town than toward the two nearest villages despite its being significantly farther away than the two nearest communities. Although Tsimane do show sexual dimorphism in foraging tasks, Tsimane women have extensive daily and lifetime travel, and the local environment lacks directional cues that typically enhance male navigation. This study raises the possibility that greater similarity in mobility patterns because of overlapping subsistence strategies and activities may result in convergence of some male and female navigation abilities. (shrink)

In this third and last paper on inner models we consider some of the inherent limitations of the method of using inner models of the type defined in 1.2 for the proof of consistency results for the particular system of set theory under consideration. Roughly speaking this limitation may be described by saying that practically no further consistency results can be obtained by the construction of models satisfying the conditions of theorem 1.5, i.e., conditions 1.31, 1.32, 1.33, 1.51, viz.:This applies (...) in particular to the ‘complete models’ defined in 1.4. Before going on to a precise statement of these limitations we shall consider now the theorem on which they depend. This is concerned with a particular type of complete model examples of which we call “proper complete models”; they are those complete models which are essentially interior to the universe, those whose classes are sets of the universe constituting a class thereof, i.e., those for which the following proposition is true:The main theorem of this paper is that the statement that there are no models of this kind can be expressed formally in the same way as the axioms A, B, C and furthermore it can be proved that if the axiom system A, B, C is consistent then so is the system consisting of axioms A, B, C, plus this new hypothesis that there exist no proper complete models. When combined with the axiom ‘V = L’ introduced by Gödel in this new hypothesis yields a system in which any normal complete model which exists has for its universal class V, the universal class of the original system. (shrink)

This handbook presents a much-needed and comprehensive exploration of the rapidly growing fields of animal welfare and law. In recent years there has been increasing attention paid to our complex, multifaceted relationships with other animals, and in particular, the depth and breadth of various societal uses of animals. This has led to a reconsideration of their moral and social status, which has sometimes challenged the interests of those who use animals. In such a contested domain, sound evidence and reasoning become (...) particularly important. Through firm commitment to such principles, this book explores the biological foundations for the moral consideration of animals, and for evolving conceptualisations of animal welfare. It reviews in detail the welfare concerns associated with numerous forms of animal use. The inclusion of key recent developments such as climate change, pandemics and antimicrobial resistance, ensure this text is among the most current in its field. The ethical implications of the various uses of animals by society are considered, and chapters provide important recommendations for reforms of practice, law or policy. The status of animal law internationally, and in major world regions, is reviewed. Finally, the book considers human behavioural change, and strategies for improving stakeholder communication and education. The handbook is essential reading for students and scholars of animal welfare, animal law and animal ethics everywhere, and for policymakers and other professionals working in the animal welfare sector. (shrink)

In Spandrels of Truth, Beall concisely presents and defends a modest, so-called dialetheic theory of transparent truth.

Dr Ian Ramsey has made considerable use of the word ‘disclosure’ in what he has to say about religion and in his attempts to give an account of the meaning of religious language. He sometimes speaks of ‘discernment’ or ‘insight’ but ‘disclosure’ is the word he normally favours. In what follows I shall ask: what a disclosure is, to what extent Dr Ramsey's use of the notion leads to confusions, and what questions have to be faced in order to resolve (...) these confusions. (shrink)

In an article in Philosophy R. G. Swinburne set out to argue that none of Hume's formal objections to the design argument ‘have any validity against a carefully articulated version of the argument’ . This, he maintained, is largely because Hume's criticisms ‘are bad criticisms of the argument in any form’ . The ensuing controversy between Swinburne and Olding 1 has focused upon the acceptable/unacceptable aspects of the dualism presupposed in Swinburne's defence of the design argument; upon whether any simplification (...) is achieved by reducing scientific explanation to agent explanation; and upon the problems which arise from taking a man's acting upon his body as the analogy for understanding a disembodied agent acting upon matter. In this article I shall refer to the Swinburne-Olding controversy when appropriate but my main concern is to return to Swinburne's original article and argue, seriatim , that Hume's individual criticisms of the design argument are for the most part a great deal more powerful than Swinburne allowed. I shall contend that cumulatively they destroy the design argument as any sort of rational foundation for theistic belief. But first I shall indicate briefly the character of the argument together with one or two of the distinctions and refinements in terms of which it has been found helpful to carry on the discussion in recent years. (shrink)

Consequence is at the heart of logic, and an account of consequence offers a vital tool in the evaluation of arguments. This text presents what the authors term as 'logical pluralism' arguing that the notion of logical consequence doesn't pin down one deductive consequence relation; it allows for many of them.

A good argument is one whose conclusions follow from its premises; its conclusions are consequences of its premises. But in what sense do conclusions follow from premises? What is it for a conclusion to be a consequence of premises? Those questions, in many respects, are at the heart of logic (as a philosophical discipline). Consider the following argument: 1. If we charge high fees for university, only the rich will enroll. We charge high fees for university. Therefore, only the rich (...) will enroll. There are many different things one can say about this argument, but many agree that if we do not equivocate (if the terms mean the same thing in the premises and the conclusion) then the argument is valid, that is, the conclusion follows deductively from the premises. This does not mean that the conclusion is true. Perhaps the premises are not true. However, if the premises are true, then the conclusion is also true, as a matter of logic. This entry is about the relation between premises and conclusions in valid arguments. (shrink)

Semantic and soritical paradoxes challenge entrenched, fundamental principles about language - principles about truth, denotation, quantification, and, among others, 'tolerance'. Study of the paradoxes helps us determine which logical principles are correct. So it is that they serve not only as a topic of philosophical inquiry but also as a constraint on such inquiry: they often dictate the semantic and logical limits of discourse in general. Sixteen specially written essays by leading figures in the field offer new thoughts and arguments (...) about the paradoxes. (shrink)