The fossil record plays a key role in reconstructing deep evolutionary relationships through its documentation of the early diverging stem groups leading to extant phyla. In the middle Cambrian Burgess Shale, two famously problematic worms, Odontogriphus and Wiwaxia, have recently been reinterpreted as stem‐group molluscs based on their shared expression of a putative radula and putative ctenidia in Odontogriphus.1 More detailed analysis of these fossil structures, however, reveals pronounced anatomical and histological discrepancies with molluscan analogues, such that they are more (...) reliably interpreted as primitive features of the superphylum Lophotrochozoa. In the absence of any obviously derived characters, Odontogriphus could be placed in the stem group of the Lophotrochozoa or on the stem of any of its constituent phyla, whereas the dorsal covering of chaetae in Wiwaxia identifies it as a stem‐group polychaete. Despite their close relationship, these two jawed, segmented worms could conceivably represent the early stages of two separate phyla. BioEssays 28: 1161–1166, 2006. © 2006 Wiley Periodicals, Inc. (shrink)

This paper defends the idea that there might be vagueness or indeterminacy in the world itself---as opposed to merely in our representations of the world---against the charges of incoherence and unintelligibility. First we consider the idea that the world might contain vague *properties and relations*; we show that this idea is already implied by certain well-understood views concerning the semantics of vague predicates (most notably the fuzzy view). Next we consider the idea that the world might contain vague *objects*; we (...) argue that an object is indeterminate in a certain respect (colour, size, etc.) just in case it is a borderline case of a maximally specific colour (size, etc.) property. Finally we consider the idea that the *world as a whole* might be indeterminate; we argue that the world is indeterminate just in case it lacks a determinate division into determinate objects. (shrink)

Logic is essential to correct reasoning and also has important theoretical applications in philosophy, computer science, linguistics, and mathematics. This book provides an exceptionally clear introduction to classical logic, with a unique approach that emphasizes both the hows and whys of logic. Here Nicholas Smith thoroughly covers the formal tools and techniques of logic while also imparting a deeper understanding of their underlying rationales and broader philosophical significance. In addition, this is the only introduction to logic available today that (...) presents all the major forms of proof--trees, natural deduction in all its major variants, axiomatic proofs, and sequent calculus. The book also features numerous exercises, with solutions available on an accompanying website. -/- Logic is the ideal textbook for undergraduates and graduate students seeking a comprehensive and accessible introduction to the subject. -/- Provides an essential introduction to classical logic Emphasizes the how and why of logic Covers both formal and philosophical issues Presents all the major forms of proof--from trees to sequent calculus Features numerous exercises, with solutions available online The ideal textbook for undergraduates and graduate students . (shrink)

There is an extensive literature on time travel in both philosophy and physics. Part of the great interest of the topic stems from the fact that reasons have been given both for thinking that time travel is physically possible—and for thinking that it is logically impossible! This entry deals primarily with philosophical issues; issues related to the physics of time travel are covered in the separate entries on time travel and modern physics and time machines. We begin with the definitional (...) question: what is time travel? We then turn to the major objection to the possibility of backwards time travel: the Grandfather paradox. Next, issues concerning causation are discussed—and then, issues in the metaphysics of time and change. We end with a discussion of the question why, if backwards time travel will ever occur, we have not been visited by time travellers from the future. (shrink)

Life works best when people value us for more than our looks. In these pages, Model and a philosopher friend reflect on the subtleties of life, revealing insights and finding ways to develop deeper, more meaningful ties with our own inner self and the other people in our lives.

The notion of 'freedom' is essential to America's view of itself as a democratic and individual-based society. In this philosophical dialogue, characters assess the many facets, implications and apparent contradictions inherent in this deceptively complex idea. Seventy-nine short segments provide food for thought even in stolen moments of reading pleasure. The book sparkles with intellectually stimulating views. Drawing on the tradition of the Platonic dialogue, 'On Freedom' explores what freedom is and what it means through the discussions of two characters (...) (Director and Friend). Topics include Slavery, Responsibility, Anarchy, Wealth, Love, Courage, Authority, Inhibition, Happiness, Discipline, Vigilance. The characters arrive at no simple or absolute definition of freedom. But that doesn't mean they don't finish with a better idea of what freedom is than when they started. If anything, they come to appreciate the need for clarity about their subject. And they come to see that such clarity necessarily involves complexity. Readers with no philosophical training can enjoy this book, while readers with a philosophy background can enjoy the way it treats an old, familiar theme with a lighter touch. Families will value 'On Freedom' for enabling younger readers, too, to explore philosophic ideas of general interest and importance. (shrink)

A philosophical treatment of ideas, the book presents a philosophical dialogue much in the spirit of classical philosophical dialogues, notably those of Plato and Xenophon. As those authors do in a number of their works, Nick Pappas adopts a light and playful tone to treat a serious topic. This contrast helps bring out the truth, in an approachable style that requires no prior exposure to philosophy and heavy intellectual work.

"Rule" adopts the tradition of political philosophy begun by Socrates, refined by Xenophon and Plato. The book concentrates on something the characters call life-without-rule. What would that be? Is it a sort of utopia? How does it differ from anarchy? What makes it so appealing and what are the trade-offs?

A many-valued (aka multiple- or multi-valued) semantics, in the strict sense, is one which employs more than two truth values; in the loose sense it is one which countenances more than two truth statuses. So if, for example, we say that there are only two truth values—True and False—but allow that as well as possessing the value True and possessing the value False, propositions may also have a third truth status—possessing neither truth value—then we have a many-valued semantics in the (...) loose but not the strict sense. A many-valued logic is one which arises from a many-valued semantics and does not also arise from any two-valued semantics [Malinowski, 1993, 30]. By a ‘logic’ here we mean either a set of tautologies, or a consequence relation. We can best explain these ideas by considering the case of classical propositional logic. The language contains the usual basic symbols (propositional constants p, q, r, . . .; connectives ¬, ∧, ∨, →, ↔; and parentheses) and well-formed formulas are defined in the standard way. With the language thus specified—as a set of well-formed formulas—its semantics is then given in three parts. (i) A model of a logical language consists in a free assignment of semantic values to basic items of the non-logical vocabulary. Here the basic items of the non-logical vocabulary are the propositional constants. The appropriate kind of semantic value for a proposition is a truth value, and so a model of the language consists in a free assignment of truth values to basic propositions. Two truth values are countenanced: 1 (representing truth) and 0 (representing falsity). (ii) Rules are presented which determine a truth value for every proposition of the language, given a model. The most common way of presenting these rules is via truth tables (Figure 1). Another way of stating such rules—which will be useful below—is first to introduce functions on the truth values themselves: a unary function ¬ and four binary functions ∧, ∨, → and ↔ (Figure 2).. (shrink)

In an earlier paper I argued that time travellers cannot change the past: alleged models of changing the past either fall into contradiction or else involve avoiding, not changing, the past. Goddu has responded to my argument, maintaining that his hypertime model involves time travellers changing (not avoiding) the past. In the present paper I first discuss what would be required to substantiate the claim that a given model involves changing rather than avoiding the past. I then consider Goddu's hypertime (...) model and an earlier model due to Meiland. I argue that neither author does what would be required to substantiate the claim that the model involves changing (not avoiding) the past. I go on to give reasons for the stronger claim that no-one can present a coherent model and also substantiate the claim that it involves changing (not avoiding) the past. (shrink)

The so-called paradoxes of time travel have played a significant role in both the physics and philosophy literatures - but how much force do these alleged paradoxes really have?

One of Tarski’s stated aims was to give an explication of the classical conception of truth—truth as ‘saying it how it is’. Many subsequent commentators have felt that he achieved this aim. Tarski’s core idea of defining truth via satisfaction has now found its way into standard logic textbooks. This paper looks at such textbook definitions of truth in a model for standard first-order languages and argues that they fail from the point of view of explication of the classical notion (...) of truth. The paper furthermore argues that a subtly different definition—also to be found in classic textbooks but much less prevalent than the kind of definition that proceeds via satisfaction—succeeds from this point of view. (shrink)

Fox writes about the nomadic project for people with bodies wherever they live, in what turned out not quite to be the planned sequel to his Postmodernism, Sociology, and Health (1993), but a treatment of the very practical issue of embodiment. Aspiring to transcend the conceptualization of embodiment by modern medicine, the caring professions, and other institutions, he suggests that it is possible to have a non-essentialist yet becoming body, not a being-body, not to be trammelled by notions of health (...) and illness. Distributed in the US by ISBS. Annotation copyrighted by Book News, Inc., Portland, OR. (shrink)

In VAGUENESS AND DEGREES OF TRUTH, Nicholas Smith develops a new theory of vagueness: fuzzy plurivaluationism. -/- A predicate is said to be VAGUE if there is no sharply defined boundary between the things to which it applies and the things to which it does not apply. For example, 'heavy' is vague in a way that 'weighs over 20 kilograms' is not. A great many predicates -- both in everyday talk, and in a wide array of theoretical vocabularies, from (...) law to psychology to engineering -- are vague. -/- Smith argues, based on a detailed account of the defining features of vagueness, that an accurate theory of vagueness must involve the idea that truth comes in degrees. The core idea of degrees of truth is that while some sentences are true and some are false, others possess intermediate truth values: they are truer than the false sentences, but not as true as the true ones. Degree-theoretic treatments of vagueness have been proposed in the past, but all have encountered significant objections. In light of these, Smith develops a new type of degree theory. Its innovations include a definition of logical consequence that allows the derivation of a classical consequence relation from the degree-theoretic semantics, a unified account of degrees of belief and their relationships with degrees of truth and subjective probabilities, and the incorporation of semantic indeterminacy -- the view that vague statements need not have unique meanings -- into the degree-theoretic framework. -/- As well as being essential reading for those working on vagueness, Smith's book provides an excellent entry-point for newcomers to the area -- both from elsewhere in philosophy, and from computer science, logic and engineering. It contains a thorough introduction to existing theories of vagueness and to the requisite logical background. (shrink)

Postmodernism and poststructuralism challenge fundamental positions in social theory. This book sets out some of the components of a postmodern social theory of health and healing, deriving from theorists including Derrida, Deleuze and Guattari, Foucault, Cixous and Kristeva. Nicholas J. Fox observes that the knowledge of the medical profession about the body, illness and health supplies the basis for medical dominance. The body of the patient is inscribed by discourses of professional `care,' an interaction which subjectifies the patient. Fox (...) explores the character of this power - and how it may be, and is, resisted. The book illustrates with detailed examples how the organization of health care and the caring relationship itself are sites for this contestation of power. Elements of feminist theory, and Derridean concepts of diffrance and intertextuality, supply the framework for the politics and ethics of the postmodern position on health. Deleuze and Guattari's radical challenge to psychoanalysis and familial repetitions within the healer/patient contact allows a re-reading of central ideas in medical sociology. While focusing upon the possibilities of postmodern social theory, the book demands a reappraisal of issues of structure, identity and knowledge in modernist medical sociology. Modernist sociology, Fox suggests, has been complicit in the creation of `the patient,' and of 'health' and 'illness.' Written with an emphasis on accessibility, this book explores the practical consequences of postmodern theory as well as familiarizing the reader with the concepts of postmodernism. (shrink)

Contains exercises and solutions to accompany Logic: The Laws of Truth by Nicholas J. J. Smith (Princeton University Press, 2012).

Philosophers, linguists and others interested in problems concerning natural language frequently employ tools from logic and model theory. The question arises as to the proper interpretation of the formal methods employed—of the relationship between, on the one hand, the formal languages and their set-theoretic models and, on the other hand, the objects of ultimate interest: natural language and the meanings and truth conditions of its constituent words, phrases and sentences. Two familiar answers to this question are descriptivism and instrumentalism. More (...) recently, a third answer has been proposed: the logic as modelling view. This paper seeks to clarify and assess this view of logic. The conclusion is that we can successfully adopt the modelling perspective on a given piece of logical machinery only if we have to hand some other machinery to which we take the descriptive attitude. Thus, logic as modelling is not a full-fledged alternative to the descriptive view— for it cannot stand alone: it can at best be an addition to the descriptive perspective. The paper first presents the argument in a general, abstract form, before working through a detailed case study. The case examined is the one with respect to which the logic as modelling view has been developed in the greatest detail in the literature: the case of fuzzy model theory as an account of vagueness in natural language. (shrink)

A requirement on any theory of vagueness is that it solve the sorites paradox. It is generally agreed that there are two aspects to such a solution: one task is to locate the error in the sorites argument; the second task is to explain why the sorites reasoning is a paradox rather than a simple mistake. I argue for a further constraint on approaches to the second task: they should conform to the standard modus operandi in formal semantics, in which (...) the semantic theory one develops is taken to be implicit in the ordinary usage of competent speakers. Thus it should not turn out that one's explanation of why ordinary speakers react to the sorites reasoning in the way they do depends on speakers not thinking that the semantics of vague language is governed by the theory one is advocating. I then argue that, out of the current main contenders for a theory of vagueness, only theories that posit degrees of truth can meet this further constraint. (shrink)

It's Game Time!: Games to Enhance Classroom Learning enables the teacher to decide when and how to use games to effectively complement their teaching philosophy and style to meet the needs of their students by providing over 40 games that can be used in any class at any level.

In this paper, I discuss one form of the idea that spacetime and gravity might ‘emerge’ from quantum theory, i.e. via a holographic duality, and in particular via AdS/CFT duality. I begin by giving a survey of the general notion of duality, as well as its connection to emergence. I then review the AdS/CFT duality and proceed to discuss emergence in this context. We will see that it is difficult to find compelling arguments for the emergence of full quantum gravity (...) from gauge theory via AdS/CFT, i.e. for the boundary theory's being metaphysically more fundamental than the bulk theory. (shrink)

This book, based on the prestigious Oxford Amnesty Lecture series, focuses on human rights abuses, and the ways in which they are interpreted. The collection includes contributions by Tzvetan Todorov, Michael Ignatieff, Peter Singer, Gitta Sereny, Susan Sontag, and Eva Hoffman, with commentaries on their essays by Niall Fergusson, Timothy Garton Ash, John Broome, Hermione Lee and others.

Three characters with different skills and outlooks explore the idea of education, exploring what true education is, challenging common conceptions and putting forward rich definitions of education and what it ideally would be.

Is it always better to be active than passive? Is passivity a sign of cowardice - or prudence? Are people who keep their thoughts to themselves passive, or might they be actively preparing for well-considered future actions? Seemingly simple concepts turn out to be deeper and more significant than they first appear.

This paper presents a new solution to the problems for orthodox decision theory posed by the Pasadena game and its relatives. I argue that a key question raised by consideration of these gambles is whether evaluative compositionality (as I term it) is a requirement of rationality: is the value that an ideally rational agent places on a gamble determined by the values that she places on its possible outcomes, together with their mode of composition into the gamble (i.e. the probabilities (...) assigned to them)? The paper first outlines a certain simple response to the Pasadena game and identifies two problems with this response, the second of which is that it leads to a wholesale violation of evaluative compositionality. I then argue that rationality does not require decision makers to factor in outcomes of arbitrarily low probability. A method for making decisions which flows from this basic idea is then developed, and it is shown that this decision method (Truncation) leads to a limited — as opposed to wholesale — violation of evaluative compositionality. The paper then argues that the truncation method yields solutions to the problems posed by the Pasadena game and its relatives that are both attractive in themselves and superior to those yielded by alternative proposals in the literature. (shrink)

This paper argues that the most famous objection to backward time travel can carry no weight. In its classic form, the objection is that backward time travel entails the occurrence of impossible things, such as auto-infanticide—and hence is itself impossible. David Lewis has rebutted the classic version of the objection: auto-infanticide is prevented by coincidences, such as time travellers slipping on banana peels as they attempt to murder their younger selves. I focus on Paul Horwich‘s more recent version of the (...) objection, according to which backward time travel entails not impossible things, but improbable ones—such as the string of slips on banana peels that would be required to stop a determined auto-infanticidal maniac from murdering her younger self—and hence is itself highly improbable. I argue that backward time travel does not entail unusual numbers of coincidences; and that, even if it did, that would not render its occurrence unlikely. (shrink)

This article investigates and resolves the question whether gauge symmetry can display analogs of the famous Galileo’s ship scenario. In doing so, it builds on and clarifies the work of Greaves and Wallace on this subject.

As a prolegomenon to understanding the sense in which dualities are theoretical equivalences, we investigate the intuitive `equivalence' of hyper-regular Lagrangian and Hamiltonian classical mechanics. We show that the symplectification of these theories provides a sense in which they are isomorphic, and mutually and canonically definable through an analog of `common definitional extension'.

The "justice of markets" is intricately connected to the treatment of the poor and the disadvantaged in market economies. The increased interest of multinational corporations in low-income market segments affords, on one hand, the opportunity for a more inclusive capitalism, and on the other, the threat of greater exploitation of poor and disadvantaged consumers. This article traces the contributions of Catholic Social Teaching and its basic principles toward providing insight into what constitutes "justice" in such "marketing to the impoverished" situations.

In a warm and enjoyable dialogue the meaning of health, in its fullest sense, becomes a philosophical issue as much as a biological. For isn't the essence of health a general sense of well-being? Health can be seen as reflecting satisfaction with our quality of life; but how do we achieve that? Here, a character who is heading off for a job teaching health has an extended conversation with a trusted mentor, and they test various definitions, various visions, and some (...) of the infinite possibilities of the idea of health, in the process coming to a deeper and more invigorating understanding of life itself. They arrive at the notion of symbiosis - a living together to the advantage of each. And isn't a good conversation a sort of living together to the advantage of each? In such dialogue, we engage with our hearts and minds. When are we more alive than that? What is the peak of health if not this life, this engagement? The two friends want to know what health is. But they want more: They want to be healthy. They see three basic types of health - bodily, mental, and societal. These three types affect one another. How they affect one another matters in a critical way. But there is more. A friendly conversation allows special access to what is critical. Our guard is down in such a conversation. We are less likely to be defensive. We are more likely to keep our minds open and clear. We are likely to feel the confidence it takes to learn. (shrink)

A philosophical treatment of the idea of authority, this book is a dialogue between three characters. "Director," a philosopher, challenges the others to think through their ideas of authority, how it is established, how it works, and how it can be either subtle or bold.

Killing the Arab Spring tells the stories of the Arab Spring uprising in 15 Middle East states, from the point of view of a secular Middle Eastern political analyst familiar with the politics, the culture of the people and the history of the area. Dr. Hasan views the vast majority of the Arab rulers deriving their absolute authority from inheritance or military coups, or in the case of the Saudis from conquest, not at the pleasure of the governed. Arab leaders (...) do not believe that government is a trust on behalf of the people. They believe that if there is democracy and their societies are composed of equal and competing individuals, there will be a tendency towards anarchy. People involved in the Arab Spring uprisings demanded inclusive and equitable democracy, social justice and economic development. There were no civil society institutions strong enough to challenge the weapons of authoritarianism that included ideology, repression, payoffs and the solidarity of the crony capitalists. The author argues that Saddam Hussein’s 1980 war on Iran was the spark that started a chain of bloody wars and events which eventually led to the US invasion of Iraq and the Arab Spring uprisings. The revolts and the counter revolts took different forms in each country based on its history, the type of government and the economy. The author argues that the Arab Spring is a step of a long process toward democracy rather than an aberration between periods of authoritarian regimes. To understand the Arab Spring causes and its aftermath, the book provides the reader with a review of the Middle East common culture that includes the history of Islamic religion, Islamic-sects and Arab tribalism, and brief history of each country. There are few activities more controversial than writing history of a nation involved in a conflict. Even while witnessing history unfolding in a country, different historians provide different narratives, different causes and different conclusions. This becomes more obvious when the history of the conflicts is viewed through the prism of the politics of sectarianism ethnicity and tribalism. The author strives for an objective view, but he does not hide his strong support to liberal democracy and human rights. (shrink)

Violence and reason are related, if only because violence is done to reason every single day. All it takes is to fail to listen. Everything else, all the real violence, starts right there, including tough talk in lieu of rational argument and the violence of not allowing us to think things through. In a virtual conversation with other thoughtful people, we can evaluate and refine our own positions, gaining clarity and confidence.

This article uncovers a foundational relationship between the ‘gauge symmetry’ of a Newton-Cartan theory and the celebrated Trautman Recovery Theorem and explores its implications for recent philosophical work on Newton-Cartan gravitation.

This paper presents a new argument against A-theories of time. A-theorists hold that there is an objective now (present moment) and an objective flow of time, the latter constituted by the movement of the objective now through time. A-theorists therefore want to draw different pictures of reality—showing the objective now in different positions—depending upon the time at which the picture is drawn. In this paper it is argued that the times at which the different pictures are drawn may be taken (...) to be normal times or hypertimes. If they are normal times then the A-theory is inconsistent, or else collapses to the B-theory—and appealing to primitive tense operators will not help A-theorists avoid this conclusion. If the times are hypertimes then the A-theory is consistent, but deeply problematic none the less. (shrink)