Relationships are central to human life strategies and have crucial fitness consequences. Yet, at the same time, they incur significant maintenance costs that are rarely considered in either social psychological or evolutionary studies. Although many social psychological studies have explored their dynamics, these studies have typically focused on a small number of emotionally intense ties, whereas social networks in fact consist of a large number of ties that serve a variety of different functions. In this study, we examined how entire (...) active personal networks changed over 18 months across a major life transition. Family relationships and friendships differed strikingly in this respect. The decline in friendship quality was mitigated by increased effort invested in the relationship, but with a striking gender difference: relationship decline was prevented most by increased contact frequency (talking together) for females but by doing more activities together in the case of males. (shrink)

This paper examines social network size in contemporary Western society based on the exchange of Christmas cards. Maximum network size averaged 153.5 individuals, with a mean network size of 124.9 for those individuals explicitly contacted; these values are remarkably close to the group size of 150 predicted for humans on the basis of the size of their neocortex. Age, household type, and the relationship to the individual influence network structure, although the proportion of kin remained relatively constant at around 21%. (...) Frequency of contact between network members was primarily determined by two classes of variable: passive factors (distance, work colleague, overseas) and active factors (emotional closeness, genetic relatedness). Controlling for the influence of passive factors on contact rates allowed the hierarchical structure of human social groups to be delimited. These findings suggest that there may be cognitive constraints on network size. (shrink)

This volume is a collection of original essays by eminent philosophers written for R. B. Braithwaite's eightieth birthday to celebrate his work and teaching. In one way or another, all the essays reflect his central concern with the impact of science on our beliefs about the world and the responses appropriate to that. Together they testify to the signal importance of his contributions in areas of philosophy bearing on this concern: the philosophy of science, especially of the statistical sciences, theories (...) of belief and of probability, decision theory and games theory. This book, which includes a full bibliography of Professor Braithwaite's work, will interest advanced students and professionals in the fields of philosophy and psychology. (shrink)

To controlforceaccurately under a wide range of behavioral conditions, the central nervous system would either require a detailed, continuously updated representation of the state of each muscle (and the load against which each is acting) or else force feedback with sufficient gain to cope with variations in the properties of the muscles and loads. The evidence for force feedback with adequate gain or for an appropriate central representation is not sufficient to conclude that force is the major controlled variable in (...) normal limb movements.Morton's hypothesis, thatlengthis controlled by a follow-up servo, has a number of difficulties related to the delays, gains, variability, and specificity in feedback pathways comprising potential servo loops. However, experimental evidence is consistent with these pathways providing servo assistance for some movements produced by coactivation of α- and static γ-motoneurons. Dynamic γ-motoneurons may provide an additional input for adaptive control of different types of movements.The idea that feedback is used to compensate for changes in musclestiffnesshas received experimental support under static postural conditions. However, reflexes tend to increase rather than decrease the range of variation in muscle stiffness during some cyclic movements. Theoretical problems associated with the regulation of stiffness are also discussed. The possibilities of separate control systems forvelocityorviscosityare considered, but the evidence is either negative or lacking. I conclude that different physical variables can be controlled depending on the type of limb movement required. The concept of stiffness regulation is also useful under some conditions, but should probably be extended to the regulation of the visco-elastic properties (i.e., the mechanical impedance) of a muscle or joint. (shrink)

In this paper a formalized logic of propositions, PA1, is presented. It is proven consistent and its relationships to traditional logic, to PM ([15]), to subjunctive (including contrary-to-fact) implication and to the “paradoxes” of material and strict implication are developed. Apart from any intrinsic merit it possesses, its chief significance lies in demonstrating the feasibility of a general logic containing theprinciple of subjunctive contrariety, i.e., the principle that ‘Ifpwere true thenqwould be true’ and ‘Ifpwere true thenqwould be false’ are incompatible.

The idea that bureaucracy is a «rational» and «depoliticized» instrument in the conduct of public affairs, has recently come under severe criticism. Assuming the inevitable trend towards «politicization», modern bureaucracies can possibly be classified info four different categories, i.e. : «De-politicized», «Semi-politicized», «Committed» and «Fully-politicized». Such a classification is based on the operationalization of certain indices on four different dimensions viz. a) Degree of Bureaucracy's Influence in Decision-making; b) Degree of its Involvement in Political Activities; c) Degree of Political Interference (...) in its Work and d) its Image in the Public. The extent of «politicization» of any bureaucratic system and its actual deviation from the defined categories will, however, depend upon the available pattern of the characteristic indices in that particular society. Notwithstanding certain difficulties in the operationalization of such indices, the model should be helpful in providing a framework for a comparative analysis and measurement of «politicization» of bureaucracies in different political systems. (shrink)

Faith and reason and self-realization in Islam.

This book is not a study of Plato's philosophy, but a contribution to the literary interpretation of the dialogues, through analysis of their formal structure, ...

R.G. Collingwood defined historical knowledge as essentially ‘scientific’, and saw the historian's task as the ‘re-enactment of past thoughts’. The author argues the need to go beyond Collingwood, first by demonstrating the authenticity of available evidence, and secondly, using Namier as an example, by considering methodology as well as epistemology, and the need to relate past thoughts to their present context. The ‘law of the consumption of time’ encourages historians to focus on landmark events, theories and generalisations, thus breaking from (...) Collingwood's emphasis on fidelity to past ideas and interpreting the past from the concepts of the present. This conflict can only be reconciled by the study of historiography. (shrink)

The question of whether or not children may be used as subjects in non-therapeutic research projects has generated a great deal of debate and received answers varying from 'no, never' to 'yes, if societal interests are served'. It has been claimed that a Kantian, deontological ethics would necessarily rule out such research, since valid consent would be impossible. The present paper gives a deontological argument for allowing children to be subjects in certain types of research.

Marcus Aurelius, Roman emperor from 161 to 180 A.D., is renowned for his just rule and long frontier wars. But his lasting fame rests on his Meditations, a bedside book of reflections and self-admonitions written during his last years, that provide unique insights into the mind of an ancient ruler and contain many passages of pungent epigram and poetic imagery. This study is designed to make the Meditations more accessible to the modern reader. Rutherford carefully explains the historical and philosophical (...) background, charts the main themes and tendencies of Marcus's thought, and relates stylistic detail to the intellectual and moral outlook of the author. His goal is to define Marcus's aims, attitudes, and styles more precisely and restore his work to the position it held in the past, that of a spiritual classic which can be read and enjoyed by people who are not professional scholars. (shrink)

It is the aim of this paper to examine certain aspects of a point of view which has attracted much attention in physical methodology. This is the standpoint known as operationalism. We wish to discuss its significance in the construction and interpretation of physical theories.The essential meaning of operationalism in physics is that physical concepts should be defined in terms of actual physical operations. On this view there is no meaning to a concept unless it represents an operation which can (...) be performed in the laboratory. Thus the term “pressure of a gas” signifies nothing until an operation is described which constitutes the measurement of pressure. When one thinks of pressure one must think. of some actual apparatus, such as, for example, some glass and rubber tubing and some mercury and certain operations performed using these until finally one gets a pointer reading which one calls the pressure of the gas. The same stand is taken with respect to length, time, velocity, acceleration, temperature, etc. (shrink)

R.G. Collingwood defined historical knowledge as essentially ‘scientific’, and saw the historian's task as the ‘re-enactment of past thoughts’. The author argues the need to go beyond Collingwood, first by demonstrating the authenticity of available evidence, and secondly, using Namier as an example, by considering methodology as well as epistemology, and the need to relate past thoughts to their present context. The ‘law of the consumption of time’ encourages historians to focus on landmark events, theories and generalisations, thus breaking from (...) Collingwood's emphasis on fidelity to past ideas and interpreting the past from the concepts of the present. This conflict can only be reconciled by the study of historiography. (shrink)

It is a common complaint against moral philosophers that their abstract theorising bears little relation to the practical problems of everyday life. Professor Braithwaite believes that this criticism need not be inevitable. With the help of the Theory of Games he shows how arbitration is possible between two neighbours, a jazz trumpeter and a classical pianist, whose performances are a source of mutual discord. The solution of the problem in the lecture is geometrical, and is based on the formal analogy (...) between the logic of the situation and the geometry of a parabola. But an appendix provides the alternative algebraic treatment of a general two-person collaboration situation. (shrink)

This book addresses the logical aspects of the foundations of scientific theories. Even though the relevance of formal methods in the study of scientific theories is now widely recognized and regaining prominence, the issues covered here are still not generally discussed in philosophy of science. The authors focus mainly on the role played by the underlying formal apparatuses employed in the construction of the models of scientific theories, relating the discussion with the so-called semantic approach to scientific theories. The book (...) describes the role played by this metamathematical framework in three main aspects: considerations of formal languages employed to axiomatize scientific theories, the role of the axiomatic method itself, and the way set-theoretical structures, which play the role of the models of theories, are developed. The authors also discuss the differences and philosophical relevance of the two basic ways of aximoatizing a scientific theory, namely Patrick Suppes’ set theoretical predicates and the "da Costa and Chuaqui" approach. This book engages with important discussions of the nature of scientific theories and will be a useful resource for researchers and upper-level students working in philosophy of science. (shrink)

Changes being introduced to deregulate the Dutch health care system after decades of extensive state control are to be welcomed, and will in future require consumers to be ‘well‐informed, cost‐conscious and assertive patients, who are aware of their responsibility for their own health.’ R.B. Kool MD, PhD and E.J.J.M. Kimman PhD are attached to the Department of Business Ethics in the Faculty of Economics and Econometrics at The Free University, P.O. Box 7161, 10107 MC Amsterdam.