Flexible work arrangements (FWAs) are widely offered in public accounting as a tool to retain valued professional staff. Previous research has shown that participants in FWAs are perceived to be less likely to succeed in their careers in public accounting than individuals in public accounting who do not participate in FWAs (Cohen and Single, 2001). Research has also documented an increasing backlash against family–friendly policies in the workplace as placing unfair burdens on individuals without children. Building directly on a (...) previous study in this journal (Cohen and Single, 2001), this study addresses the issue of whether the documented perceptions toward FWA participants are the result of electing to take part in the FWA or the result of bias against employees with children. The research questions are addressed in a 3 × 2 experimental setting in which we manipulate FWA participation, along with family status and gender of a hypothetical manager in a public accounting firm. Our findings indicate that FWA participants are viewed as less likely to advance and as less committed than individuals without children or individuals who had children but who were not taking part in a FWA. Male FWA participants are viewed as less likely to succeed than female FWA participants. This effect appears to arise from a perception that FWA participants are willing to make sacrifices in their careers to accommodate family needs and thus may not be as committed to making the sacrifices perceived as necessary to meet the rigorous demands of the public accounting environment. This raises the ethical question of what could be done to change the culture in public accounting to foster a substantive support system for individuals who want to balance a family and a career. (shrink)

Flexible work arrangements (FWAs) are widely offered in public accounting as a tool to retain valued professional staff. Previous research has shown that participants in FWAs are perceived to be less likely to succeed in their careers in public accounting than individuals in public accounting who do not participate in FWAs (Cohen and Single, 2001). Research has also documented an increasing backlash against family–friendly policies in the workplace as placing unfair burdens on individuals without children. Building directly on a (...) previous study in this journal (Cohen and Single, 2001), this study addresses the issue of whether the documented perceptions toward FWA participants are the result of electing to take part in the FWA or the result of bias against employees with children. The research questions are addressed in a 3 × 2 experimental setting in which we manipulate FWA participation, along with family status and gender of a hypothetical manager in a public accounting firm. Our findings indicate that FWA participants are viewed as less likely to advance and as less committed than individuals without children or individuals who had children but who were not taking part in a FWA. Male FWA participants are viewed as less likely to succeed than female FWA participants. This effect appears to arise from a perception that FWA participants are willing to make sacrifices in their careers to accommodate family needs and thus may not be as committed to making the sacrifices perceived as necessary to meet the rigorous demands of the public accounting environment. This raises the ethical question of what could be done to change the culture in public accounting to foster a substantive support system for individuals who want to balance a family and a career. (shrink)

Objectives To evaluate whether the requirement of “minimal risk and burden” for paediatric research without direct benefit to the subjects compromises the ability to obtain data necessary for improving paediatric care. To provide evidence-based reflections on the EU recommendation that allows for a higher level of risk. Design and setting Systematic analysis of the approval/rejection decisions made by the Dutch Central Committee on Research involving Human Subjects (CCMO). Review methods The analysis included 165 proposals for paediatric research without direct benefit (...) that were reviewed by the CCMO between January, 2000, and July, 2007. A separate, in-depth analysis of all drug studies included 18 early phase drug studies and nine other drug studies without direct benefit. Results 11 out of 165 studies were definitively rejected because the CCMO did not regard the risk and/or burden to be minimal. In three of these 11 cases (including two early phase drug studies) the requirement of minimal risk and burden was cited as the only reason for rejection. Four other early phase drug studies also involved risks and/or burdens that were not regarded to be minimal but were nevertheless approved. Conclusions The requirement of minimal risk and burden, aiming to protect research subjects, occasionally leads to rejection of protocols. Early phase drug studies relatively often do not comply with the requirement. Committees may find ways to approve important studies that formally should be rejected, but that is not a desirable solution. The regulatory framework should be revised to make such occasional exceptions to the requirement legitimate and transparent. (shrink)

Live donor kidney transplantation is the best treatment option for most patients with late-stage chronic kidney disease; however, the rate of living kidney donation has declined in the United States. A consensus conference was held June 5-6, 2014 to identify best practices and knowledge gaps pertaining to live donor kidney transplantation and living kidney donation. Transplant professionals, patients, and other key stakeholders discussed processes for educating transplant candidates and potential living donors about living kidney donation; efficiencies in the living donor (...) evaluation process; disparities in living donation; and financial and systemic barriers to living donation. We summarize the consensus recommendations for best practices in these educational and clinical domains, future research priorities, and possible public policy initiatives to remove barriers to living kidney donation. (shrink)

In some cases people judge it morally acceptable to sacrifice one person’s life in order to save several other lives, while in other similar cases they make the opposite judgment. Researchers have identified two general factors that may explain this phenomenon at the stimulus level: (1) the agent’s intention (i.e. whether the harmful event is intended as a means or merely foreseen as a side-effect) and (2) whether the agent harms the victim in a manner that is relatively “direct” or (...) “personal”. Here we integrate these two classes of findings. Two experiments examine a novel personalness/directness factor that we call personal force, present when the force that directly impacts the victim is generated by the agent’s muscles (e.g., in pushing). Experiments 1a and b demonstrate the influence of personal force on moral judgment, distinguishing it from physical contact and spatial proximity. Experiments 2a and b demonstrate an interaction between personal force and intention, whereby the effect of personal force depends entirely on intention. These studies also introduce a method for controlling for people’s real-world expectations in decisions involving potentially unrealistic hypothetical dilemmas. (shrink)

Traditional theories of moral development emphasize the role of controlled cognition in mature moral judgment, while a more recent trend emphasizes intuitive and emotional processes. Here we test a dual-process theory synthesizing these perspectives. More specifically, our theory associates utilitarian moral judgment (approving of harmful actions that maximize good consequences) with controlled cognitive processes and associates non-utilitarian moral judgment with automatic emotional responses. Consistent with this theory, we find that a cognitive load manipulation selectively interferes with utilitarian judgment. This interference (...) effect provides direct evidence for the influence of controlled cognitive processes in moral judgment, and utilitarian moral judgment more specifically. (shrink)

ABSTRACT This paper is intended to stimulate debate amongst stakeholders in the international research community on the topic of returning individual genetic research results to study participants. Pharmacogenetics and disease genetics studies are becoming increasingly prevalent, leading to a growing body of information on genetic associations for drug responsiveness and disease susceptibility with the potential to improve health care. Much of these data are presently characterized as exploratory (non‐validated or hypothesis‐generating). There is, however, a trend for research participants to be (...) permitted access to their personal data if they so choose. Researchers, sponsors, patient advocacy groups, ethics committees and regulatory authorities are consequently confronting the issue of whether, and how, study participants might receive their individual results. Noted international ethico‐legal guidelines and public policy positions in Europe and the United States are reviewed for background. The authors offer ‘Points‐to‐Consider’ regarding returning research results in the context of drug development trials based on their knowledge and experience. These considerations include: the clinical relevance of data, laboratory qualifications, informed consent procedures, confidentiality of medical information and the competency of persons providing results to participants. The discussion is framed as a benefit‐to‐risk assessment to balance the potential positive versus negative consequences to participants, while maintaining the integrity and feasibility of conducting genetic research studies. (shrink)

Evolutionary developmental biology (evo-devo) has undergone dramatic transformations since its emergence as a distinct discipline. This paper aims to highlight the scope, power, and future promise of evo-devo to transform and unify diverse aspects of biology. We articulate key questions at the core of eleven biological disciplines—from Evolution, Development, Paleontology, and Neurobiology to Cellular and Molecular Biology, Quantitative Genetics, Human Diseases, Ecology, Agriculture and Science Education, and lastly, Evolutionary Developmental Biology itself—and discuss why evo-devo is uniquely situated to substantially improve (...) our ability to find meaningful answers to these fundamental questions. We posit that the tools, concepts, and ways of thinking developed by evo-devo have profound potential to advance, integrate, and unify biological sciences as well as inform policy decisions and illuminate science education. We look to the next generation of evolutionary developmental biologists to help shape this process as we confront the scientific challenges of the 21st century. (shrink)

Plato's Euthyrphro, Apology, andCrito portray Socrates' words and deeds during his trial for disbelieving in the Gods of Athens and corrupting the Athenian youth, and constitute a defense of the man Socrates and of his way of life, the philosophic life. The twelve essays in the volume, written by leading classical philosophers, investigate various aspects of these works of Plato, including the significance of Plato's characters, Socrates's revolutionary religious ideas, and the relationship between historical events and Plato's texts.

This commentary serves as a reply to Hoffart and Johnson’s article contending that psychodynamic psychotherapy (PDT) models cannot be examined with regard to mechanism of change or represent within-person causal relationships. Hoffart and Johnson cite purportedly paradigmatic examples of PDT and cognitive therapy and examine them with respect to Kazdin’s requirements for investigation of mechanisms of change. We highlight inaccuracies in Hoffart and Johnson’s representation of PDT and, in doing so, provide reasoning in support of the empirical examinability of PDT. (...) We conclude by recommending a metatheoretical system (i.e., functionalism) and empirical methodologies that clinical scientists may consider when investigating mechanisms of PDT in the future. (shrink)

Neokantismes: la marque du pluriel indique d'emblee que le mot d'ordre des annees 1865 Retour a Kant! regroupe differentes ecoles. Les auteurs dont les textes inedits en francais se trouvent ici rassembles et traduits, appartiennent en effet soit a l'ecole de Marbourg (H. Cohen, P. Natorp et E. Cassirer) soit a l'ecole de Bade (W. Windelband, H. Rickert, E. Lask, J. Cohn). Le point commun du neokantisme logique des premiers et du neokantisme axiologique des seconds consiste en une volonte (...) d'asseoir le positivisme sur un fondement philosophique respectueux de l'attitude phenomenologique. Kant apparut donc a tous ces penseurs comme science rigoureuse a condition toutefois de ne considerer le sujet transcendantal que comme une fonction logique de la pensee qui elabore la forme et le contenu de la connaissance. A condition egalement de ne pas limiter l'entreprise critique a la physique, mais de l'etendre au fondement de toutes les sciences de l'esprit. (shrink)

Applying machine learning algorithms to automatically infer relationships between concepts from large-scale collections of documents presents a unique opportunity to investigate at scale how human semantic knowledge is organized, how people use it to make fundamental judgments (“How similar are cats and bears?”), and how these judgments depend on the features that describe concepts (e.g., size, furriness). However, efforts to date have exhibited a substantial discrepancy between algorithm predictions and human empirical judgments. Here, we introduce a novel approach to generating (...) embeddings for this purpose motivated by the idea that semantic context plays a critical role in human judgment. We leverage this idea by constraining the topic or domain from which documents used for generating embeddings are drawn (e.g., referring to the natural world vs. transportation apparatus). Specifically, we trained state-of-the-art machine learning algorithms using contextually-constrained text corpora (domain-specific subsets of Wikipedia articles, 50+ million words each) and showed that this procedure greatly improved predictions of empirical similarity judgments and feature ratings of contextually relevant concepts. Furthermore, we describe a novel, computationally tractable method for improving predictions of contextually-unconstrained embedding models based on dimensionality reduction of their internal representation to a small number of contextually relevant semantic features. By improving the correspondence between predictions derived automatically by machine learning methods using vast amounts of data and more limited, but direct empirical measurements of human judgments, our approach may help leverage the availability of online corpora to better understand the structure of human semantic representations and how people make judgments based on those. (shrink)

Le mouvement général des sciences est de fournir les moyens théoriques d'une reconstruction des phénomènes, en élaborant des lois explicitant leurs régularités sous-jacentes. Aujourd'hui, l'attitude générale en sciences repose sur l'a priori des déterminismes, quelle que soit leur forme. La pensée humaine, dans ses rapports au monde, est une confrontation permanente aux systèmes complexes qui nous habitent et dans lesquels nous habitons. Chacun des systèmes possède une histoire propre qui le rend singulier et source continue de surprises. On se prend (...) à le penser comme système autonome avec ses lois et ses degrés de liberté interne. Quand il s'agit de penser l'être humain, la tentation est encore plus forte de lui prêter un libre arbitre. La question fondamentale est donc celle de la compatibilité entre la pensée scientifique en quête de déterminismes, et la compréhension des complexités, génératrice d'indéterminismes. Comment obtenir une conciliation quand, de la physique à l'éthique, en passant par la cellule biologique, les êtres multicellulaires et les sociétés, on remonte les niveaux d'organisation? Peut-on y parvenir quant à l'être humain et la société sans remettre en question certains aspects cruciaux comme la responsabilité et l'éthique? Ce livre a pour but de revisiter ce débat fondamental, auquel fleuri Atlan a consacré une grande partie de son œuvre, en s'appuyant, d'une part, sur les approches récentes de la modélisation des systèmes complexes et, d'autre part, sur la tradition philosophique multimillénaire. (shrink)

“de-extinction” refers to the process of resurrecting extinct species by genetic methods. This science-fiction-sounding idea is in fact already in early processes of scientific implementation. Although this recent “revival of the dead” raises deep ethical questions, the ethics of de-extinction has barely received philosophical treatment. Rather than seeking a verdict for or against de-extinction, this paper attempts an overview and some novel analyses of the main ethical considerations. Five dimensions of the ethics of de-extinction are explored: (a) the possible contribution (...) of de-extinction to promoting ecological values, (b) the deontological argument that we owe de-extinction to species we rendered extinct, (c) the question of “playing God” through de-extinction, (d) the utilitarian perspective, and (e) the role of aesthetic considerations in the ethics of de-extinction. A general feature arising from the paper’s discussion is that, due to de-extinction’s special character, it repeatedly tests the limits of our ethical notions. (shrink)

Increased investment in ethics education has prompted a variety of instructional objectives and frameworks. Yet, no systematic procedure to classify these varying instructional approaches has been attempted. In the present study, a quantitative clustering procedure was conducted to derive a typology of instruction in ethics education. In total, 330 ethics training programs were included in the cluster analysis. The training programs were appraised with respect to four instructional categories including instructional content, processes, delivery methods, and activities. Eight instructional approaches were (...) identified through this clustering procedure, and these instructional approaches showed different levels of effectiveness. Instructional effectiveness was assessed based on one of nine commonly used ethics criteria. With respect to specific training types, Professional Decision Processes Training and Field-Specific Compliance Training appear to be viable approaches to ethics training based on Cohen’s d effect size estimates. By contrast, two commonly used approaches, General Discussion Training and Norm Adherence Training, were found to be considerably less effective. The implications for instruction in ethics training are discussed. (shrink)

Representations of the fingers are embodied in our cognition and influence performance in enumeration tasks. Among deaf signers, the fingers also serve as a tool for communication in sign language. Previous studies in normal hearing (NH) participants showed effects of embodiment (i.e., embodied numerosity) on tactile enumeration using the fingers of one hand. In this research, we examined the influence of extensive visuo‐manual use on tactile enumeration among the deaf. We carried out four enumeration task experiments, using 1–5 stimuli, on (...) a profoundly deaf group (n = 16) and a matching NH group (n = 15): (a) tactile enumeration using one hand, (b) tactile enumeration using two hands, (c) visual enumeration of finger signs, and (d) visual enumeration of dots. In the tactile tasks, we found salient embodied effects in the deaf group compared to the NH group. In the visual enumeration of finger signs task, we controlled the meanings of the stimuli presentation type (e.g., finger‐counting habit, fingerspelled letters, both or neither). Interestingly, when comparing fingerspelled letters to neutrals (i.e., not letters or numerical finger‐counting signs), an inhibition pattern was observed among the deaf. The findings uncover the influence of rich visuo‐manual experiences and language on embodied representations. In addition, we propose that these influences can partially account for the lag in mathematical competencies in the deaf compared to NH peers. Lastly, we further discuss how our findings support a contemporary model for mental numerical representations and finger‐counting habits. (shrink)

The goal of this thesis is to model some of the cognitive structures and processes involve d in how people decide what to say in purposeful conversation. The main concern is to show how a speaker's knowledge of his/her hearer influences what s/he says. Utterances in such dialogues, where speakers can be presumed to be speaking for reasons, can best be viewed as the performance of "speech acts" (e.g., requesting). By modeling the process of deciding what to say as one (...) of problem-solving, we show that the same mechanisms used to plan non-linguistic actions are applicable to planning of speech acts. The methodology of this research employs a computer program that integrates beliefs, goals, problem-solving, and reasoning, with the use of language. The program does this by planning speech acts when it determines that to achieve its situational goals, it needs to influence someone else's behavior. The system is able to plan request speech actrions to influence its user's goals, and inform speech acts to influence his/her beliefs. In addition, it is shown that speech acts can be used to achieve subgoals of other such acts. For instance, in addition to requesting that the user perform some action, the system can also decide to supply him/her with information necessary to performing that action -- information that it believes s/he does not already have. Our model is extendable to the more general problem of planning multiparty speech acts -- ones where actions requested by the speaker involve acts to be performed by parties other than the hearer. [MORE]. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:29. CONTRARIETY AND CAUSALITY IN HUME Hume's notion of contrariety ranks among the most obscure in his theory of relations. To make matters worse, the puzzling account of contrariety he offers can be shown inconsistent in the following way. The Treatise (T69-82) divides all relations into two disjoint classes - one class containing relations of knowledge (in the strict sense) ascertained by the mere comparison of ideas, the other (...) containing those of probability or 'uncertain knowledge' requiring 'experience' or empirical evidence. Causality is the paradigm of a probability relation - contrariety falls into the class of knowledge relations. Thus unlike causality the discovery of a contrary relation appears to require no experience. Yet in direct contradiction Hume claims that with the exception of existence and non-existence (which are singled out for special attention), all knowledge of contrary relations demands experience: no two ideas are in themselves contrary, except those of existence and non-existence.... All other objects, such as fire and water, heat, and cold, are only found to be contrary from experience, and from the contrariety of their 'causes ' or effects '. (T15) The charge of inconsistency appears inevitable. However, I shall argue that Hume escapes by implicitly operating with two distinct concepts of contrariety: one (which I shall term "logical contrariety") a relation of knowledge, the other (to be called "empirical contrariety") reducible to a peculiar type of causal relation, and therefore a probability relation. To adduce independent grounds for this claim I demonstrate that acceptance of these two concepts is essential if we are to explain why Hume finds 2 it important to place the following restriction on contra- 30. riety (hereafter, R): properly speaking no objects are contrary to each other, but existence an (y exists). And (4) can hardly be said to represent a form of contrariety between existent and non-existent objects. (Indeed paradox of material implication aside, (4) is an analysis of "x causes y".) Therefore to hold R and still maintain some sense of contrariety between existent and non-existent objects, Hume must restrict contrariety to logical contrariety. 32. Hume's own remarks bear out my claim. In the Treatise he recognizes that restricting contrariety to existence and non-existence means treating it as contradiction : the flattest of all contradictions... (is)... that 'tis possible for the same thing both to be and not to be. (T19, my emphasis.)... with contrariety... No one can once doubt but existence and non-existence destroy each other, and are perfectly incompatible and contrary. (T70) And in the Enquiries he interchanges the terms 'contrary' and 'negation' : The contrary of every matter of fact is still possible ; because it can never imply a contradiction... (EU25)... No negation of a fact can involve a contradiction. (EU164) This usage indicates that if? is (logically) contrary to q,? is -q, the negation of q. In this case the conjunction of? and q spells the contradiction (q & -q). The definition of logical contrariety we adopt is the same as the definition of contradiction specialized to existential sentences, so we need not state it. It is sufficient to give as a paradigm the following contradiction: (5)(Mars exists) & - (Mars exists). Here it is the existence of Mars that is logically contrary to the non-existence of Mars and therefore the contrariety restriction R is satisfied. Again it is only the existence and non-existence of the same object that is logically contrary. Empirical contrariety is most clearly defined in terms of the Lewis counterfactual G=>, where 1O' is a monadic predicate, 'e.' and 'e.' represent distinct arbitrary events, and "0(e)" means "event e occurs": 33. 5 Here it is not the existence and non-existence or occurrence (EC) e. is empirically contrary to e. iff 0(e.) D=> ~0(e.)." and non-occurrence of distinct events that gives rise to contrariety. Rather it is the existence or occurrence of one event that is empirically contrary to the existence or occurrence of another. To establish Hume's motivation for framing the condition R in such a way as to identify contrariety with contradiction, I now turn to examine the epistemological ground of the difference between empirical and logical contrariety. The ontological distinction between empirical... (shrink)

A is for Alice and astronomers arguing about acceleration -- B is for Bernard's body-exchange machine -- C is for the Catholic cannibal -- D is for Maxwell's demon -- E is for evolution (and an embarrassing problem with it) -- F is for the forms lost forever to the prisoners of the cave -- G is for Galileo's gravitational balls -- H is for Hume's shades -- I is for the identity of indiscernibles -- J is for Henri Poincaré (...) and alternative geometries -- K is for the Kritik and Kant's kind of thought experiments -- L is for Lucretius' spear -- M is for Mach's motionless chain -- N is for Newton's bucket -- O is for Olbers' paradox -- P is for Parfit's person -- Q is for the questions raised by thought experiments quotidiennes -- R is for the rule-ruled room -- S is for Salvatius' ship, sailing along its own space-time line -- T is for the time-travelling twins -- U is for the universe, and Einstein's attempts to understand it -- V is for the vexed case of the violinist -- W is for Wittgenstein's beetle -- X is for xenophanes and thinking by examples -- Y is for counterfactuals and a backwards approach to history -- Z is for Zeno and the mysteries of infinity. (shrink)

Many writers in various fields--philosophy, religion, literature, and psychology--believe that the question of the meaning of life is one of the most significant problems that an individual faces. In The Meaning of Life, Second Edition, E.D. Klemke collects some of the best writings on this topic, primarily works by philosophers but also selections from literary figures and religious thinkers. The twenty-seven cogent, readable essays are organized around three different perspectives on the meaning of life. In Part I, the readings assert (...) and defend the theistic view that without the existence of God--or faith in God--life has no significance or purpose. In Part II the selections deny this thesis, defending instead the humanistic alternative--that life has or can have meaning and worth without any theistic beliefs or commitment. In the final group of readings, contributors ask if the question of the meaning of life is in itself legitimate and significant. The volume also includes an introduction by the editor and a selected bibliography. This new edition adds essays by A. J. Ayer, Hazel Barnes, William Lane Craig, Owen Flanagan, Antony Flew, Thomas Nagel, Kai Nielsen, Philip L. Quinn, Arthur Schopenhauer, and Walter T. Stace. The only anthology of its kind, The Meaning of Life, Second Edition, is ideal for courses in introduction to philosophy and human nature. It also provides an accessible and stimulating introduction to the subject for general readers. (shrink)

Talvez “redescobrimento” seja uma caracterização adequada para designar o _status_ do movimento neokantiano atualmente. Se, por um lado, o neokantismo tem recebido uma maior atenção em diversos lugares da Europa, América do norte, Ásia, e em alguns países da América Latina, por outro, na ainda jovem cultura filosófica brasileira, o estudo desse importante e decisivo movimento é algo atípico dentro de nossas instituições de ensino, para dizer o mínimo. De fato, a quantidade de trabalhos acadêmicos, artigos e livros sobre as (...) filosofias de autores como Cassirer, Windelband, Cohen, Lask, Natorp, Rickert e tantos outros que fizeram parte desse plural movimento filosófico está muito aquém do que eles realmente merecem. Sem dúvidas, esse “acerto de contas” com tais personagens seria uma tarefa muito mais árdua se não tivéssemos à nossa disposição os _Estudos_ _Neokantianos_, do Professor Mario Ariel González Porta. (shrink)

Davis called for “extreme caution” in the use of non-invasive brain stimulation to treat neurological disorders in children, due to gaps in scientific knowledge. We are sympathetic to his position. However, we must also address the ethical implications of applying this technology to minors. Compensatory trade-offs associated with NIBS present a challenge to its use in children, insofar as these trade-offs have the effect of limiting the child’s future options. The distinction between treatment and enhancement has some normative force here. (...) As the intervention moves away from being a treatment toward being an enhancement—and thus toward a more uncertain weighing of the benefits, risks, and costs—considerations of the child’s best interests diminish, and the need to protect the child’s autonomy looms larger. NIBS for enhancement involving trade-offs should therefore be delayed, if possible, until the child reaches a state of maturity and can make an informed, personal decision. NIBS for treatment, by contrast, is permissible insofar as it can be shown to be at least as safe and effective as currently approved treatments, which are themselves justified on a best interests standard. (shrink)

Haack, S. Is truth flat or bumpy?--Chihara, C. S. Ramsey 's theory of types.--Loar, B. Ramsey 's theory of belief and truth.--Skorupski, J. Ramsey on Belief.--Hookway, C. Inference, partial belief, and psychological laws.--Skyrms, B. Higher order degrees of belief.--Mellor, D. H. Consciousness and degrees of belief.--Blackburn, S. Opinions and chances.--Grandy, R. E. Ramsey, reliability, and knowledge.--Cohen, L. J. The problem of natural laws.--Giedymin, J. Hamilton's method in geometrical optics and Ramsey 's view of theories.