In contrast to symbolic or associationist representations, I advocate a third form of representing information that employs geometrical structures. I argue that this form is appropriate for modelling concept learning. By using the geometrical structures of what I call conceptual spaces, I define properties and concepts. A learning model that shows how properties and concepts can be learned in a simple but naturalistic way is then presented. I also discuss the advantages of the geometric approach over the symbolic and associationist (...) traditions. (shrink)
We survey the theory of Mucnik and Medvedev degrees of subsets of $^{\omega}{\omega}$with particular attention to the degrees of $\Pi_{1}^{0}$ subsets of $^{\omega}2$. Sections 1-6 present the major definitions and results in a uniform notation. Sections 7-6 present proofs, some more complete than others, of the major results of the subject together with much of the required background material.
This is a study of how self-transformation may occur through the practice of reframing one's personal experience in terms of a canonical language: that is, a system of symbols that purports to explain something about human beings and the universe they live in. The Christian conversion narrative is used as the primary example here, but the approach used in this book also illuminates other practices such as psychotherapy in which people deal with emotional conflict through language.
A simple treatment of chemical equilibrium is given, based on Boltzmann’s distribution law. The results are compared with those obtained by using thermodynamics.
In recent years, observational techniques at cosmological distances have been sufficiently improved that cosmology has become an empirical science, rather than a field for unchecked speculation. There remains the fact that its object, the whole universe, exists only once; hence, we are unable to separate “general” features from particular aspects of “our” universe. This might not be a serious drawback if we were justified in the belief that presently accepted laws of nature remain valid on the cosmological scale. In the (...) author's opinion, however, there are grounds for doubting that belief. The three arguments presented are (1) the possibility that apparent constants of nature may, during cosmological times, turn out to vary (Dirac conjecture); (2) the effective breakdown of the principle of relativity caused by the effects of the cosmological environment on local experiments; and (3) the fact that present theory leads to field singularities at the early stages of the expanding universe, which might be a signal that currently accepted theoretical concepts are inadequate for an understanding of highly condensed matter. (shrink)
The basis of the Periodic Table is discussed. Electronic configuration recurs in only 21 out of the 32 groups. A better basis is derived by considering the highest classical valency (v) exhibited by an element and a new measure, the highest valency in carbonyl compounds (v*). This leads to a table based on the number of outer electrons possessed by an atom (N) and the number of electrons required for it to achieve an inert (noble) gas configuration (N*). Periodicity of (...) these is nearly complete. The new basis helps to settle the question of the best form of table and related issues. (shrink)
Our aim in this paper is to suggest that most current theories of global justice fail to adequately recognise the importance of global public goods. Broadly speaking, this failing can be attributed at least in part to the complexity of the global context, the individualistic focus of most theories of justice, and the localised nature of the theoretical foundations of most theories of global justice. We argue ? using examples (particularly that of protecting antibiotic efficacy) ? that any truly effective (...) theory of global justice must recognise the importance of global public goods. Global public goods confer significant benefits to individuals yet can only be effectively promoted and preserved through collective action and the restriction of individual choice; something which most theories of justice are structurally unequipped to sufficiently promote. (shrink)
For much of the 20th century, vulnerability to deprivations of health has often been defined by geographical and economic factors. Those in wealthy, usually ‘Northern’ and ‘Western’, parts of the world have benefited from infrastructures, and accidents of geography and climate, which insulate them from many serious threats to health. Conversely, poorer people are typically exposed to more threats to health, and have lesser access to the infrastructures needed to safeguard them against the worst consequences of such exposure. However, in (...) recent years the increasingly globalized nature of the world’s economy, society and culture, combined with anthropogenic climate change and the evolution of antibiotic resistance, has begun to shift the boundaries that previously defined the categories of person threatened by many exogenous threats to health. In doing so, these factors expose both new and forgotten similarities between persons, and highlight the need for global cooperative responses to the existential threats posed by climate change and the evolution of antimicrobial resistance. In this article, we argue that these emerging health threats, in demonstrating the similarities that exist between even distant persons, provides a catalyst for global solidarity, which justifies, and provides motivation for, the establishment of solidaristic, cooperative global health infrastructures. (shrink)
(2000). ‘Nothing is, but what is not’: Utopias as practical political philosophy. Critical Review of International Social and Political Philosophy: Vol. 3, The Philosophy of Utopia, pp. 9-24.
The valencies of the lanthanides vary more than was once thought. In addition to valencies associated with a half-full shell, there are valencies associated with a quarter- and three-quarter-full shell. This can be explained on the basis of Slater’s theory of many-electron atoms. The same theory explains the variation in complexing constants in the trivalent state. Valency in metallic and organometallic compounds is also discussed.
The major normative recommendations in the literature on food risk communication can be summarized in the form of seven practical principles for such communication: (1) Be honest and open. (2) Disclose incentives and conflicts of interest. (3) Take all available relevant knowledge into consideration. (4) When possible, quantify risks. (5) Describe and explain uncertainties. (6) Take all the public's concerns into account. (7) Take the rights of individuals and groups seriously. We show that each of these proposed principles can be (...) justified both in terms of more fundamental ethical principles and instrumentally in terms of the communicating agent's selfinterest. The mechanisms of this concordance of justifications are discussed. It is argued that the concordance is specific for areas such as food risks in which agents such as companies and public authorities are highly dependent on the public's trust and confidence. The implications of these findings both for moral philosophy and for practical food risk communication are discussed. (shrink)
Examining a variety of texts ranging from the Ancient Near East to the nineteenth century, this book deals with the inevitable presence of both fact and fiction ...
In public goods experiments, stochastic choice, censoring and motivational heterogeneity give scope for disagreement over the extent of unselfishness, and whether it is reciprocal or altruistic. We show that these problems can be addressed econometrically, by estimating a finite mixture model to isolate types, incorporating double censoring and a tremble term. Most subjects act selfishly, but a substantial proportion are reciprocal with altruism playing only a marginal role. Isolating reciprocators enables a test of Sugden’s model of voluntary contributions. We estimate (...) that reciprocators display a self-serving bias relative to the model. (shrink)
Whilst it is generally accepted that breast-feeding lowers the likelihood of conception, this relationship is not straightforward and there appears to be a wide variation in the effectiveness of the association between individual mother-infant pairs. Up to about 6 months post-partum breast-feeding probably can be used as a family planning method, with up to 98% effectiveness if behavioural guidelines are adhered to . But beyond this time significant variations appear between different countries, and even different communities within countries, which make (...) any overall recommendation impossible. To understand the reasons for variation in the duration of lactational infecundity it is necessary to understand the mechanisms involved, but knowledge of these processes is still far from complete. There are, nevertheless, enough data to indicate that suckling and maternal milk output are intimately linked with the return of fecundity. (shrink)
The partial ordering of Medvedev reducibility restricted to the family of Π0 1 classes is shown to be dense. For two disjoint computably enumerable sets, the class of separating sets is an important example of a Π0 1 class, which we call a ``c.e. separating class''. We show that there are no non-trivial meets for c.e. separating classes, but that the density theorem holds in the sublattice generated by the c.e. separating classes.
The paper shows that the past, “history” in a non-technical sense, can be changed in quantum mechanics. The first part of the paper reviews Deutsch's analysis in his paper of 1991. It is demonstrated that Deutsch assumes the existence of a multiplicity of essentially classical worlds. Such a multiplicity of worlds would allow the past to be changed in classical mechanics. It is argued that the existence of multiple “classical” worlds is not required by quantum mechanics. It is then shown (...) that it is possible to change the past in conventional quantum mechanics even without the assumption of a multiplicity of worlds. (shrink)
