The feasibility of reversing human aging within a matter of decades has traditionally been dismissed by all professional biogerontologists, on the grounds that not only is aging still poorly understood, but also many of those aspects that we do understand are not reversible by any current or foreseeable therapeutic regimen. This broad consensus has recently been challenged by the publication, by five respected experimentalists in diverse subfields of biogerontology together with three of the present authors, of an article (Ann NY (...) Acad Sci 959, 452–462) whose conclusion was that all the key components of mammalian aging are indeed amenable to substantial reversal (not merely retardation) in mice, with technology that has a reasonable prospect of being developed within about a decade. Translation of that panel of interventions to humans who are already alive, within a few decades thereafter, was deemed potentially feasible (though it was not claimed to be likely). If the prospect of controlling human aging within the foreseeable future cannot be categorically rejected, then it becomes a matter of personal significance to most people presently alive. Consequently, we suggest that serious public debate on this subject is now warranted, and we survey here several of the biological, social and political issues relating to it. BioEssays 24:667–676, 2002. © 2002 Wiley Periodicals, Inc. (shrink)

Value, Reality, and Desire is an extended argument for a robust realism about value. The robust realist affirms the following distinctive theses. There are genuine claims about value which are true or false--there are facts about value. These value-facts are mind-independent - they are not reducible to desires or other mental states, or indeed to any non-mental facts of a non-evaluative kind. And these genuine, mind-independent, irreducible value-facts are causally efficacious. Values, quite literally, affect us. These are not particularly fashionable (...) theses, and taken as a whole they go somewhat against the grain of quite a lot of recent work in the metaphysics of value. Further, against the received view, Oddie argues that we can have knowledge of values by experiential acquaintance, that there are experiences of value which can be both veridical and appropriately responsive to the values themselves. Finally, these value-experiences are not the products of some exotic and implausible faculty of "intuition." Rather, they are perfectly mundane and familiar mental states - namely, desires. This view explains how values can be "intrinsically motivating," without falling foul of the widely accepted "queerness" objection. There are, of course, other objections to each of the realist's claims. In showing how and why these objections fail, Oddie introduces a wealth of interesting and original insights about issues of wider interest--including the nature of properties, reduction, supervenience, and causation. The result is a novel and interesting account which illuminates what would otherwise be deeply puzzling features of value and desire and the connections between them. (shrink)

What does it take for one proposition to be closer to the truth than another. In this, the first published monograph on the topic, Oddie develops a comprehensive theory that takes the likeness in truthlikeness seriously.

The article looks at the structure of impossible worlds, and their deployment in the analysis of some intentional notions. In particular, it is argued that one can, in fact, conceive anything, whether or not it is impossible. Thus a semantics of conceivability requires impossible worlds.

This a general account of the school of Mo-tzu, its social basis as a movement of craftsmen, its isolated place in the Chinese tradition, and the nature of its later contributions to logic, ethics, and science. It assesses the relation of Mohist thinking to the structure of the Chinese language, and grapples with the textual dynamics of later Mohist writings, particularly in regard to grammar and style, technical terminology, the use and significance of stock examples, and overall organization. Includes edited (...) and annotated Chinese text with an English translation and commentary, a glossary, and a photographic reproduction of the unemended text from the Taoist Patrology. (shrink)

Why should a Bayesian bother performing an experiment, one the result of which might well upset his own favored credence function? The Ramsey-Good theorem provides a decision theoretic answer. Provided you base your decision on expected utility, and the the experiment is cost-free, performing the experiment and then choosing has at least as much expected utility as choosing without further ado. Furthermore, doing the experiment is strictly preferable just in case at least one possible outcome of the experiment could alter (...) your choice of options. That is, you should pursue the information just in case it could make a difference to what you do. The problem remains, however, why one should do an experiment when nothing of much practical consequence hangs in the balance. One possibility here is to invoke the pure cognitive utility of states. It is shown that one constraint on cognitive value (what I call cogency) guarantees the value of learning: from a cognitive point of view you are justified in performing an experiment if the outcome of the experiment could make a different to what you think. A bonus of the basic framework is that it provides a new decision theoretic argument for the rationality of conditionalization. (shrink)

Two different programmes are in the business of explicating accuracy—the truthlikeness programme and the epistemic utility programme. Both assume that truth is the goal of inquiry, and that among inquiries that fall short of realizing the goal some get closer to it than others. Truthlikeness theorists have been searching for an account of the accuracy of propositions. Epistemic utility theorists have been searching for an account of the accuracy of credal states. Both assume we can make cognitive progress in an (...) inquiry even while falling short of the target. I show that the prospects for combining these two programmes are bleak. A core accuracy principle, proximity, that is universally embraced within the truthlikeness programme turns out to be incompatible with a central principle within the epistemic utility programme, namely propriety. 1Truthlikeness and Epistemic Utility 2Inquiries 3Accuracy for Propositions 4Proximity 5Accuracy for Credal States 6Propriety 7Proximity for Credal States 8Extensionality 9Admissible Weightings 10Propriety Violates Proximity 11Possible Responses 11.1Retreat to convexity 11.2Reject boundedness 11.3Reject additivity 12The Upshot. (shrink)

The paper explains how a paraconsistent logician can appropriate all classical reasoning. This is to take consistency as a default assumption, and hence to work within those models of the theory at hand which are minimally inconsistent. The paper spells out the formal application of this strategy to one paraconsistent logic, first-order LP. (See, Ch. 5 of: G. Priest, In Contradiction, Nijhoff, 1987.) The result is a strong non-monotonic paraconsistent logic agreeing with classical logic in consistent situations. It is shown (...) that the logical closure of a theory under this logic is trivial only if its closure under LP is trivial. (shrink)

When is a testimony-based belief justified? According to so-called "Anti-Reductionism," the principle that a hearer is prima facie justified to take what another tells them at face value is true. I call this position "Liberal Foundationalism." I call it "liberal" for it is more liberal than "Moderate Foundationalism" that holds that perception-based beliefs are prima facie justified but testimony-based beliefs are not. Liberal Foundationalism has two interpretations: the principle is a contingent empirical truth, or an a priori necessary truth. I (...) call the view that the principle is a priori necessary "Liberal Fundamentalism." This chapter defends Liberal Fundamentalism against objections in the first half, and then in the second half it introduces "Weak Liberal Fundamentalism," the view that it is a priori necessary that testimony provides some epistemic support, but perhaps not enough, absent defeat, for knowledge. In later work I abandon the view that the principle is a priori necessary, but I still maintain the distinction between Strong and Weak variants of the principle, and the replies to many of the objections to the principle. (shrink)

There has been a recent explosion of interest in the epistemology of disagreement. Much of the recent literature is concerned with a particular range of puzzle cases (discussed in the Cases section of my paper). Almost all of the papers that contribute to that recent literature make mention of questions about religious disagreement in ways that suggest that there are interesting connections between those puzzle cases and real life cases of religious disagreement. One important aim of my paper is to (...) cast doubt on that suggestion. More generally, the aim of my paper is to give a reasonably full account of the recent literature on the epistemology of disagreement, and then to give a serious discussion of some of the epistemological issues that are raised by real world religious disagreements. (shrink)

Many people hold that there is a distinctive notion of metaphysical necessity. In this paper I explain why I am skeptical about the view. I examine the sorts of considerations that are adduced for it, and argue that they meet equal and opposite considerations.

‘What is philosophy?’ is a question that every professional philosopher must ask themself sometimes. In a sense, of course, they know: they spend much time doing it. But in another sense, the answer to the question is not at all obvious. In the same way, any person knows by acquaintance what breathing is; but this does not mean that they know the nature of breathing: its mechanism and function. The nature of breathing, in this sense, is now well understood; the (...) nature of philosophy, by contrast, is still very much an open question. One of the reasons this is so is that the nature of philosophy is itself a philosophical question, so uncontentious answers are not to be expected—if philosophers ever ceased disagreeing with one another our profession would be done for. Moreover, it is a hard philosophical question. Many great philosophers, including Plato, Hegel, and others, have suggested answers to it. But their answers would now be given little credence. In the thirty or so years that I have been doing philosophy there have been two views about the nature of philosophy which have had wide acceptance. These are the views of the later Wittgenstein and of Derrida. In the first two parts of this paper I will describe these views and explain why I find them unsatisfactory. I will then go on, in the final part of paper, to outline a view that inspires more confidence in me. (shrink)

Theories of verisimilitude have routinely been classified into two rival camps—the content approach and the likeness approach—and these appear to be motivated by very different sets of data and principles. The question thus naturally arises as to whether these approaches can be fruitfully combined. Recently Zwart and Franssen (Synthese 158(1):75–92, 2007) have offered precise analyses of the content and likeness approaches, and shown that given these analyses any attempt to meld content and likeness orderings violates some basic desiderata. Unfortunately their (...) characterizations of the approaches do not embrace the paradigm examples of those approaches. I offer somewhat different characterizations of these two approaches, as well as of the consequence approach (Schurz and Weingartner (Synthese 172(3):415–436, 2010) which happily embrace their respective paradigms. Finally I prove that the three approaches are indeed compatible, but only just, and that the cost of combining them is too high. Any account which combines the strictures of what I call the strong likeness approach with the demands of either the content or the consequence approach suffers from precisely the same defect as Popper’s—namely, it entails the trivialization of truthlikeness. The downside of eschewing the strong likeness constraints and embracing the content constraints alone is the underdetermination of the concept of truthlikeness. (shrink)

The point of this paper is to bring together three topics: non-existent objects, mereology, and nothing. There are important inter-connections, which it is my aim to spell out, in the service of an account of the last of these.

IntroductionCurry’s paradox is well known.See, e.g., Priest , ch. 6. It comes in both set theoretic and semantic versions. Here we will concentrate on the semantic versions. Historically, these have deployed the notion of truth. Those who wish to endorse an unrestricted T-schema have mainly endorsed a logic which rejects the principle of Absorption, \\models A\rightarrow B\). High profile logics of this kind are certain relevant logics; these have semantics which show how and why this principle is not valid. Of (...) more recent times, paradoxes which are clearly in the same family have been appearing; but these concern the notion of validity itself. The standard semantics of relevant logics seem powerless to address these. But they can. This note shows how. The upshot can be seen as a return to the roots of relevant logic, in a sense to become clear.BackgroundThe Usual Curry ParadoxesLet us start with a couple of standard forms of the paradox. I .. (shrink)

A crucial question here is what, exactly, the conditional in the naive truth/set comprehension principles is. In 'Logic of Paradox', I outlined two options. One is to take it to be the material conditional of the extensional paraconsistent logic LP. Call this "Strategy 1". LP is a relatively weak logic, however. In particular, the material conditional does not detach. The other strategy is to take it to be some detachable conditional. Call this "Strategy 2". The aim of the present essay (...) is to investigate Stragey 1. It is not to advocate it. The work is simply an extended exploration of the strategy, its strengths, its weaknesses, and the various dierent ways in which it may be implemented. In the first part of the paper I will set up the appropriate background details. In the second, I will look at the strategy as it applies to the semantic paradoxes. In the third I will look at how it applies to the set-theoretic paradoxes. (shrink)

The first half of this article is critical: it develops an interpretation of Kant as trying, and failing, to limit our judgments to phenomena and abstain from making claims about noumena, and an interpretation of Wittgenstein as trying, and failing, to develop a theory of meaning that abstains from attempting to say the unsayable. On the reading offered, both Kant and Wittgenstein find themselves saying things that by their own lights cannot be said: in Kant’s case, claims about noumena, and (...) in Wittgenstein’s case, structural claims. While Kant attempts a solution of the problem which also fails, Wittgenstein bites the bullet and leaves his Tractatus, for the most part, void and meaningless. The suggested response is a dialetheic approach—either as an alternative or, potentially, as an amendment to a Kantian or Wittgensteinian theory. According to this approach, certain problems in philosophy arise from true contradictions and thus require a theory that makes sense of contradiction. A subgroup of these problems (among them the noumenal and structural issues in Kant and Wittgenstein) are about things that both are and are not ineffable. The second half of the paper develops a dialetheic account of ineffability and a concise formal theory to ensure that contradiction at the limits of language does not spread to other areas. (shrink)

Does epistemic justification aim at truth? The vast majority of epistemologists instinctively answer 'Yes'; it's the textbook response. Joseph Cruz and John Pollock surprisingly say no. In 'The Chimerical Appeal of Epistemic Externalism' they argue that justification bears no interesting connection to truth; justification does not even aim at truth. 'Truth is not a very interesting part of our best understanding' of justification (C&P 2004, 137); it has no 'connection to the truth.' A 'truth-aimed ... epistemology is not entitled to (...) carry the day' (C&P 2004, 138, emphasis added).Pollock and Cruz's argument for this surprising conclusion is of general interest for it is 'out of step with a very common view on the .. (shrink)

In early Buddhist logic, it was standard to assume that for any state of a ff airs there were four possibilities: that it held, that it did not, both, or neither. This is the catuskoti (or tetralemma). Classical logicians have had a hard time mak­ing sense of this, but it makes perfectly good sense in the se­mantics of various paraconsistent logics, such as First Degree Entailment. Matters are more complicated for later Buddhist thinkers, such as Nagarjuna, who appear to suggest (...) that none of these options , or more than one, may hold. The point of this paper is to examine the matter, including the formal logical machinery that may be appropriate. (shrink)

I argue for an evaluative theory of desire—specifically, that to desire something is for it to appear, in some way or other, good. If a desire is a non-doxastic appearance of value then it is no mystery how it can rationalize as well as cause action. The theory is metaphysically neutral—it is compatible with value idealism (that value reduces to desire), with value realism (that it is not so reducible), and with value nihilism (all appearances of value are illusory). Despite (...) this metaphysical neutrality the thesis opens up an epistemological gold mine. Non-doxastic value appearances can provide defeasible reasons for value judgements, in roughly the same way that perceptual appearances provide defeasible reasons for perceptual judgements. The paper presents a new line of argument for the evaluative theory—drawing on recent work on fitting attitudes—and rebuts some of the most pressing criticisms. (shrink)

This book provides a sustained and penetrating critique of a wide range of views in modern cognitive science and philosophy of the mind, from Turing's famous test for intelligence in machines to recent work in computational linguistic theory. While discussing many of the key arguments and topics, the authors also develop a distinctive analytic approach. Drawing on the methods of conceptual analysis first elaborated by Wittgenstein and Ryle, the authors seek to show that these methods still have a great deal (...) to offer in the field of the cognitive theory and the philosophy of mind, providing a powerful alternative to many of the positions put forward in the contemporary literature. Amoung the many issues discussed in the book are the following: the Cartesian roots of modern conceptions of mind; Searle's 'Chinese Room' thought experiment; Fodor's 'language of thought' hypothesis; the place of 'folk psychology' in cognitivist thought; and the question of whether any machine may be said to 'think' or 'understand' in the ordinary senses of these words. Wide ranging, up-to-date and forcefully argued, this book represents a major intervention in contemporary debates about the status of cognitive science an the nature of mind. It will be of particular interest to students and scholars in philosophy, psychology, linguistics and computing sciences. (shrink)

This paper articulates Sylvan's theory of mathematical objects as non-existent, by improving (arguably) his treatment of the Characterisation Postulate. It then defends the theory against a number of natural objections, including one according to which the account is just platonism in disguise.

In many philosophical traditions, it is held that reality is non-dual. Of course, to be non-dual, as opposed to dual, is itself to partake of a certain duality. If reality really is non-dual, it must transcend this duality too. But what could this mean? Can one make coherent sense of it? To keep the discussion focussed, I will locate it in one specific tradition: the Mahāyāna Buddhist tradition. The idea that ultimate reality is non-dual goes back to the earliest Mahāyāna (...) sūtras at the turn of the Common Era. Thereafter, the question of what it means to transcend duality plays a central role in Buddhist philosophy. The point that reality must transcend even the duality between duality and non-duality plays a significant role in the Chinese Sanlun philosopher Jizang (, 549–623). His discussion points the way to an answer to our problem which may be articulated with the techniques of contemporary paraconsistent logic, as we will see. (shrink)

Saul Kripke’s work on the semantics of non-normal modal logics introduced the idea of non-normal worlds, worlds where certain connectives behave differently from the way in which they behave in the worlds of normal modal logics. Such worlds may be thought of as impossible worlds, though Kripke did not, himself, talk of them in this way. Since Kripke’s invention, the notion of an impossible world has undergone much fruitful development and application. Impossible worlds may be of different kinds—or maybe different (...) degrees of impossibility; and these worlds have found application in many areas where hyperintensionality appears to play a significant role: intentional mental states, counterfactuals, meaning, property theory, to name but a few areas. But what, exactly, is an impossible world? How is it best to characterise the notion? To date, the notion is used more by example than by definition. In this paper I will investigate the question, and propose a general characterisation, suitable for all standard purposes and tastes. (shrink)

The foundations of systematics lie in ontology, not in subjective epistemology. Systems and their elements should be distinguished from classes; only the latter are constructed from similarities. The term classification should be restricted to ordering into classes; ordering according to systematic relations may be called systematization.The theory of organization levels portrays the real world as a hierarchy of open systems, from energy quanta to ecosystems; followingHartmann these systems as extended in time are considered the primary units of reality. Organization levels (...) should be distinguished from levels of differentiation within each organization level.Certain biological systems, such as species, continue to be misinterpreted as classes, particularly by logicians unfamiliar with modern biological theory. Replacement of Aristotelian definitions of species by “polytypic” definitions achieves nothing, because species are individual systems which can be defined from an ontological viewpoint only as wholes. The dispute whether classes are real per se or only in individuals is of no scientific importance; irrespective of which view is taken, any ordering of physical objects into classes constitutes an hypothesis about the structure of the real world.The distinction between essential and contingent characters is relevant only to classification. There are no universal rules for evaluating characters for purposes of systematization. Character statements do not form separate linear sequences. The search for “unit characters” in an absolute sense is futile. All real characters are reducible to relations and are in principle measurable, although there are limitations on the extent to which this can be presently achieved.The concept of the sexual species is fundamental to theories of biosystematics. Sexual species may be defined as lineages consisting at any given time of series of populations between which genetic exchange can occur and delimited in time by two successive processes of speciation. Linnaean nomenclature needs modification; in its traditional form it is appropriate only to non-truncated hierarchies, whereas real phylogenies form truncated hierarchies. In consequence of the distinction between systematization and classification it is concluded that, while taxa may be classified into age classes or evolutionary grades, their limits as taxa can be no different in either case. Classification into evolutionary grades remains an imprecise endeavour, since no general measure of evolutionary differentiation has been devised.The spatial and temporal extent of ecosystems, the postulated basic units of ecosystematics, remains unclarified. Nevertheless there are grounds for expecting progress in this field as the energetic relations between organisms become better understood. Biotic communities are not “abstract” classes, but systematic units. Physiognomic classification should not be confused with systematization of plant communities; both approaches contribute to an understanding of vegetational structure. (shrink)

Logic, in one of the many sense of that term, is a theory about what follows from what and why. Arguably, the correct theory has to be determined by abduction. Over recent years, so called logical anti-exceptionalists have investigated this matter. Current discussions have been restricted to deductive logic. However, there are also, of course, various forms of non-deductive reasoning. Indeed, abduction itself is one of these. What is to be said about the way of choosing the best theory of (...) non-deductive inferences? It would seem clear that an anti-exceptionalist should hold that essentially the same method of choice should apply to non-deductive logic. A number of issues need to be faced in the process, not the least of which is the circularity involved in an abductive justification for a theory of abduction. This paper discusses matters. (shrink)

Anselmian theists claim (a) that there is a being than which none greater can be conceived; and (b) that it is knowable on purely—solely, entirely—a priori grounds that there is a being than which none greater can be conceived. In this paper, I argue that Anselmian Theism gains traction by conflating different interpretations of the key description ‘being than which no greater can be conceived’. In particular, I insist that it is very important to distinguish between ideal excellence and maximal (...) possible excellence. At the end of my paper, I illustrate the importance of this distinction by applying my discussion to the recent defence of Anselmian Theism in Nagasawa (Philos Q 58:577–591, 2008). (shrink)

Moral dilemmas can arise from uncertainty, including uncertainty of the real values involved. One interesting example of this is that of experimentation on human embryos and foetuses, If these have a moral stauts similar to that of human persons then there will be server constraitns on what may be done to them. If embryous have a moral status similar to that of other small clusters of cells, then constraints will be motivated largely by consideration for the persons into whom the (...) embryos may develop. If the truth lies somewhere between these two extremes, the embryo having neither the full moral weight of persons, nor a completely negligible moral weight, then different kinds of constraints will be appropriate. On the face of it, in order to know what kinds of experiements, if any, we are morally justified in performing on embryos we have to know what the moral weight of the embryo is. But then an impasse threatens, for it seems implausible that we can settle with certainty the exact moral status of the human embryo. It is the purpose of this paper to show that moral uncertainty need not make rational moral justification impossible. I develop a framework which distinguishes between what is morally right/wrong, and what is morally justified/unjustified, and applies standard decision theoretic tools to the case of moral uncertainties. (This was the first published account of what has subsequently become known as Expected Moral Value Theory. An earlier version of the paper, "A decision theoretic argument against human embryo experimentation", was published in M. Fricke (ed.), Essays in honor of Bob Durrant. (University of Otago Press, 1986) 111-27.). (shrink)

The first attempt at a systematic approach to axiomatic theories of truth was undertaken by Friedman and Sheard (Ann Pure Appl Log 33:1–21, 1987). There twelve principles consisting of axioms, axiom schemata and rules of inference, each embodying a reasonable property of truth were isolated for study. Working with a base theory of truth conservative over PA, Friedman and Sheard raised the following questions. Which subsets of the Optional Axioms are consistent over the base theory? What are the proof-theoretic strengths (...) of the consistent theories? The first question was answered completely by Friedman and Sheard; all subsets of the Optional Axioms were classified as either consistent or inconsistent giving rise to nine maximal consistent theories of truth.They also determined the proof-theoretic strength of two subsets of the Optional Axioms. The aim of this paper is to continue the work begun by Friedman and Sheard. We will establish the proof-theoretic strength of all the remaining seven theories and relate their arithmetic part to well-known theories ranging from PA to the theory of ${\Sigma^1_1}$ dependent choice. (shrink)