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)

This paper is partly to get rid of some irritation which I have felt at the quite common tendency of philosophers to elucidate (for example) ‘is red’ in terms of ‘looks red’. For a relatively recent example see, for example, Frank Jackson and Robert Pargetter, ‘An Objectivist′s Guide to Subjectivism about Colour’. However rather than try to make a long list of references, I would rather say ‘No names, no pack drill’. I have even been disturbed to find the use (...) of the words ‘looks red’ that I am opposing ascribed to me by Keith Campbell in his useful article ‘David Armstrong and Realism about Colour’. I am not saying that such talk is necessarily wrong. Talk of ‘looks red’ may be a way of harmlessly referring to the behavioural discriminations with respect to colour of a human percipient. Where it is dangerous, at least to those of us who wish to argue for a broadly physicalist account of the mind, is that it may have concealed overtones of reference to epiphenomenal and irreducibly psychic properties of experiences. Moreover even if it does not do so it may be fence sitting on this issue and liable to misinterpretation. (shrink)

We study logical systems for reasoning about equations involving recursive definitions. In particular, we are interested in "propositional" fragments of the functional language of recursion FLR [18, 17], i.e., without the value passing or abstraction allowed in FLR. The "pure," propositional fragment FLR$_0$ turns out to coincide with the iteration theories of [1]. Our main focus here concerns the sharp contrast between the simple class of valid identities and the very complex consequence relation over several natural classes of models.

Messianic peacemakers: Intertextual relationships between Zechariah 9-14 and the Gospel of Matthew. This article deals with images of war, violence and peace and with the role of messianic leaders in Deutero-Zechariah and the way in which texts from Zechariah 9–14 have been interpreted in the Gospel of Matthew. The first section describes the lines of meaning in Zechariah 9–14 on the basis of word fields related to violence and universal peace. The second section discusses Deutero-Zechariah’s own position in the development (...) of messianic expectations in Old Testament texts. In the third section, the question is asked how the meaning of texts from Zechariah 9–14 about messianic leaders has been influenced by earlier prophetic texts, and how these texts in their turn have been transformed and updated in the Gospel of Matthew, which contains explicit quotations from Deutero-Zechariah in 21:5; 26:15; 26:31 and 27:9–10. The fourth section summarises some interesting semantic shifts appearing in Matthew’s gospel compared to Deutero-Zechariah. Moreover, some critical comments are presented against the idea defended in some recent studies that there is a sharp tension between Jesus’s role in Matthew as the bringer of a peaceful ethical message, and his violent and vindictive role at the final judgement. At the end of this article, the burning question is raised whether Zechariah’s and Matthew’s messages, both of which are characterised by a certain degree of exclusivity, can play a constructive role in modern multi-religious discussions about common roads leading to global peace. (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)

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.

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)

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)