We present a description of the Stern–Gerlach type experiments using only the concepts of classical electrodynamics and the Newton’s equations of motion. The quantization of the projections of the spin (or the projections of the magnetic dipole) is not introduced in our calculations. The main characteristic of our approach is a quantitative analysis of the motion of the magnetic atoms at the entrance of the magnetic field region. This study reveals a mechanism which modifies continuously the orientation of the (...) magnetic dipole of the atom in a very short time interval, at the entrance of the magnetic field region. The mechanism is based on the conservation of the total energy associated with a magnetic dipole which moves in a non uniform magnetic field generated by an electromagnet. A detailed quantitative comparison with the (1922) Stern–Gerlach experiment and the didactical (1967) experiment by J.R. Zacharias is presented. We conclude, contrary to the original Stern–Gerlach statement, that the classical explanations are not ruled out by the experimental data. (shrink)

Scholars of Plato are divided between those who emphasize the literature of the dialogues and those who emphasize the argument of the dialogues, and between those who see a development in the thought of the dialogues and those who do not. In this important book Russell Dancy focuses on the arguments and defends a developmental picture. He explains the Theory of Forms of the Phaedo and Symposium as an outgrowth of the quest for definitions canvassed in the Socratic dialogues, by (...) constructing a Theory of Definition for the Socratic dialogues based on the refutations of definitions in those dialogues, and showing how that theory is mirrored in the Theory of Forms. His discussion, notable for both its clarity and its meticulous scholarship, ranges in detail over a number of Plato's early and middle dialogues, and will be of interest to readers in Plato studies and in ancient philosophy more generally. (shrink)

In this work, the author has fashioned out of the logical and linguistic theses of his earlier books a full-scale but readily intelligible account of moral argument.

We argue that thoughts are structures of concepts, and that concepts should be individuated by their origins, rather than in terms of their semantic or epistemic properties. Many features of cognition turn on the vehicles of content, thoughts, rather than on the nature of the contents they express. Originalism makes concepts available to explain, with no threat of circularity, puzzling cases concerning thought. In this paper, we mention Hesperus/Phosphorus puzzles, the Evans-Perry example of the ship seen through different windows, and (...) Mates cases, and we believe that there are many additional applications. (shrink)

ARISTOTLE'S PROGRAM Aristotle says outright that the law of non-contradiction cannot be demonstrated: you can't prove everything, and among the things you ...

Are fictional characters such as Sherlock Holmes real? What can fiction tell us about the nature of truth and reality? In this excellent introduction to the problem of fictionalism R. M. Sainsbury covers the following key topics: what is fiction? realism about fictional objects, including the arguments that fictional objects are real but non-existent; real but non-factual; real but non-concrete the relationship between fictional characters and non-actual worlds fictional entities as abstract artefacts fiction and intentionality and the problem of irrealism (...) fictionalism about possible worlds moral fictionalism. R. M. Sainsbury makes extensive use of examples from fiction, such as Sherlock Holmes, Anna Karenina and Madame Bovary and examines the work of philosophers who have made significant contributions to the topic, including Meinong, David Lewis, and Bas Van Fraassen. Additional features include chapter summaries, annotated further reading and a glossary of technical terms, making _Fiction and Fictionalism_ ideal for those coming to the issue for the first time. (shrink)

There are simple mechanical systems that elude causal representation. We describe one that cannot be represented in a single directed acyclic graph. Our case suggests limitations on the use of causal graphs for causal inference and makes salient the point that causal relations among variables depend upon details of causal setups, including values of variables.

Recently, Bohr’s complementarity principle was assessed in setups involving delayed choices. These works argued in favor of a reformulation of the aforementioned principle so as to account for situations in which a quantum system would simultaneously behave as wave and particle. Here we defend a framework that, supported by well-known experimental results and consistent with the decoherence paradigm, allows us to interpret complementarity in terms of correlations between the system and an informer. Our proposal offers formal definition and operational interpretation (...) for the dual behavior in terms of both nonlocal resources and the couple work-information. Most importantly, our results provide a generalized information-based trade-off for the wave–particle duality and a causal interpretation for delayed-choice experiments. (shrink)

This book is divided into three parts: in Part I, R. M. Hare offers a justification for the use of philosophy of language in the treatment of moral questions, together with an overview of his moral philosophy of ‘universal prescriptivism’. The second part, and the core of the book, consists of five chapters originally presented as a lecture series under the title ‘A Taxonomy of Ethical Theories’. Hare identifies descriptivism and non‐descriptivism as the two main positions in modern moral philosophy. (...) The former he divides into Naturalism and Intuitionism, and the latter into Emotivism and Rationalism. Hare argues that all forms of descriptivism tend to lead to Relativism because the truth conditions of moral statements are culturally variant. Of the positions discussed, only Hare's own position, a form of Rationalism, which he calls Universal Prescriptivism, meets all of the requirements that an adequate ethical theory should meet. Part III consists of Hare's previously published essay ‘Could Kant have been a Utilitarian?’ (Utilitas 5, 1993). Here, Hare puts forward the controversial thesis that Kant's moral philosophy is, in its basic principles, compatible with utilitarianism. (shrink)

This book is available either individually, or as part of the specially-priced Arguments of the Philosphers Collection.

I had a strange dream, or half-waking vision, not long ago. I found myself at the top of a mountain in the mist, feeling very pleased with myself, not just for having climbed the mountain, but for having achieved my life's ambition, to find a way of answering moral questions rationally. But as I was preening myself on this achievement, the mist began to clear, and I saw that I was surrounded on the mountain top by the graves of all (...) those other philosophers, great and small, who had had the same ambition, and thought they had achieved it. And I have come to see, reflecting on my dream, that, ever since, the hard-working philosophical worms have been nibbling away at their systems and showing that the achievement was an illusion. True, their skeletons, indigestible to worms, remained, and were surprisingly similar to one another. But I was led to think again about what one can, and what one cannot, achieve in this direction. (shrink)