Navigation ability varies widely across humans. Prior studies have reported that being younger and a male has an advantage for navigation ability. However, these studies have generally involved small numbers of participants from a handful of western countries. Here, we review findings from our project Sea Hero Quest, which used a video game for mobile and tablet devices to test 3.9 million people on their navigation ability, sampling across every nation-state and from 18 to 99 years of age. Results revealed (...) that the task has good ecological validity and across all countries sufficiently sampled (N = 63), age is linked to a near-linear decline in navigation ability from the early 20s. All countries showed a male advantage, but this varied considerably and could be partly predicted by gender inequality. We found that those who reported growing up in a city were on average worse at navigating than those who grew up outside cities and that navigation performance helped identify those at greater genetic risk of Alzheimer's disease. We discuss the advantages and challenges of using a mobile app to study cognition and the future avenues for understanding individual differences in navigation ability arising from this research. (shrink)

Sculptors, architects, and painters are three professional groups that require a comprehensive understanding of how to manipulate spatial structures. While it has been speculated that they may differ in the way they conceive of space due to the different professional demands, this has not been empirically tested. To achieve this, we asked architects, painters, sculptors, and a control group questions about spatially complex pictures. Verbalizations elicited were examined using cognitive discourse analysis. We found significant differences between each group. Only painters (...) shifted consistently between 2D and 3D concepts, architects were concerned with paths and spatial physical boundedness, and sculptors produced responses that fell between architects and painters. All three differed from controls, whose verbalizations were generally less elaborate and detailed. Thus, for the case of sculptors, architects, and painters, profession appears to relate to a different spatial conceptualization manifested through a systematically contrasting way of talking about space. (shrink)

In his book, An Introduction to Christian Philosophy, Mr. Spier demonstrated his ability to give a compact exposition of the philosophy of Hermann Dooyeweerd. And now within comparatively few pages, Mr. Spier ex-posits and criticizes Existentialism, a movement noted for its obscurity and verbosity. Mr. Spier's work is of an introductory nature and does not intend to give an exhaustive account. The merit of his clear exposition and criticism is for the reader to judge. -Translator's Preface.

The majority of papers in this special issue were presented at a conference, ‘The Advancement of Science and the Dilemma of Dual Use: Why We Can’t Afford to Fail’ held on 9–10 November 2007. The conference chairman was Andrzej Górski and its patrons were UNESCO and the President of the Polish Academy of Sciences. Three additional papers on the subject of Dual Use have been included in this issue; the authors are T. A. Cavanaugh , J. Forge and D. Koepsall.

If affirmative action and other ethnicity-based social programs are justified, then J. Angelo Corlett believes it is important to come to an adequate understanding of the nature of ethnicity in general and ethnic group membership in particular. In Race, Racism, and Reparations, Corlett reconceptualizes traditional ideas of race in terms of ethnicity. As he makes clear, the answers to the questions "What is a Native American?" or "What is a Latino?" have important implications for public policy, especially for those programs (...) designed to address historic injustices and economic and social imbalances among different groups in our society. Having supplanted "race" with a well-defined concept of ethnicity, the author then analyzes the nature and function of racism. Corlett argues for a notion of racism that must encompass not only racist beliefs but also racist actions, omissions, and attempted actions. His aim is to craft a definition of racism that will prove useful in legal and public policy contexts. Corlett places special emphasis on the broad questions of whether reparations for ethnic groups are desirable and what forms those reparations should take: land, money, social programs? He addresses the need for differential affirmative action programs and reparations policies—the experiences of different ethnic groups vary greatly. Arguments for reparations to Native and African Americans are considered in light of a variety of objections that are or might be raised against them. Corlett articulates and critically analyzes a number of possible proposals for reparations. (shrink)

How do thought and language manage to be 'about' aspects of the world? J. Robert G. Williams investigates how representation arises out of a fundamentally non-representational world, showing the explanatory relations between the representational properties of language, of thought, and of perception and intention.

Editors’ Note: A major goal of Science and Engineering Ethics is to promote discussion of the ethical issues raised by various aspects of science and engineering, both within the pages of this journal and beyond. We are beginning a series of case presentations and discussions in the Educational Forum. We invite readers to respond to the case and accompanying commentaries, and to submit other cases and commentaries for future publication. We look forward to hearing from you. — S. J. Bird, (...) R. E. Spier. (shrink)

I argue physicalism should be characterized as the thesis that all behavior is law-governed. This characterization captures crucial desiderata for a formulation of physicalism, including its broad import and worldview defining features. It also has more local virtues, such as avoiding Hempel’s dilemma. A particularly important implication, I argue, is that this thesis makes the question of the mind’s physicality turn on what the mind can do- rather than what experience is like.

This comprehensive text shows how various notions of logic can be viewed as notions of universal algebra providing more advanced concepts for those who have an introductory knowledge of algebraic logic, as well as those wishing to delve into more theoretical aspects.

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.

Extensively classroom-tested, Possibilities and Paradox provides an accessible and carefully structured introduction to modal and many-valued logic. The authors cover the basic formal frameworks, enlivening the discussion of these different systems of logic by considering their philosophical motivations and implications. Easily accessible to students with no background in the subject, the text features innovative learning aids in each chapter, including exercises that provide hands-on experience, examples that demonstrate the application of concepts, and guides to further reading.

Built in the centre of Copenhagen, and noted for its equestrian stairway, the Rundetaarn, was intended as an astronomical observatory. Part of a complex of buildings that once included a university library, it affords expansive views of the city in every direction, towering above what surrounds it. The metaphor of the towering figure, who sees what others might not, whose vantage point allows him to visualize how things fit together, and who has an earned-stature of respect and authority, fits another (...) Danish stalwart, Hans Vilhelm Hansen, whose contributions to the fields of informal logic and argument theory have earned the gratitude of his colleagues, and inspired this collection of essays, written to express the appreciation of its authors and of the many, many colleagues they represent. (shrink)