In large, impersonal moral orders many of us wish to maintain good will toward our fellow citizens only if we are reasonably sure they will maintain good will toward us. The mutual maintaining of good will, then, requires that we somehow communicate our intentions to one another. But how do we actually do this? The current paper argues that when we engage in moral responsibility practices—that is, when we express our reactive attitudes by blaming, praising, and resenting—we communicate a desire (...) to maintain good will to those in the community we are imbedded in. Participating in such practices alone will not get the job done, though, for expressions of our reactive attitudes are often what economists call cheap talk. But when we praise and blame in cases of moral diversity, expressions of our reactive attitudes act as costly signals capable of solving our social dilemma. (shrink)

We use a public-good experiment to analyze behavior in a decentralized asymmetric punishment institution. The institution is asymmetric in the sense that players differ in the effectiveness of their punishment. At the aggregate level, we observe remarkable similarities between outcomes in asymmetric and symmetric punishment institutions. Controlling for the average punishment effectiveness of the institutions, we find that asymmetric punishment institutions are as effective in fostering cooperation and as efficient as symmetric institutions. At the individual level, we find that players (...) with higher punishment effectiveness contribute similar amounts to the public account, but have higher earnings and punish more than their weak counterparts. (shrink)

When people must either save a greater number of people from a smaller harm or a smaller number from a greater harm, do their choices reflect a reasonable moral outlook? We pursue this question with the help of an experiment. In our experiment, two-fifths of subjects employ a similarity heuristic. When alternatives appear dissimilar in terms of the number saved but similar in terms of the magnitude of harm prevented, this heuristic mandates saving the greater number. In our experiment, this (...) leads to choices that are inconsistent with all standard theories of justice. We argue that this demonstrates the untrustworthiness of distributive judgments in cases that elicit similarity-based choice. (shrink)

Brian Pitts has recently claimed to show via straightforward calculation that, at least in the case of Hamiltonian electromagnetism, an arbitrary first-class constraint ``generates not a gauge transformation, but a bad physical change'' (Annals of Physics 351 (2014) pp.382-406; arXiv:1310.2756). We show, via a straightforward calculation, that a transformation generated by an arbitrary first-class constraint relates gauge-equivalent phase space points, vindicating orthodoxy. Pitts, however, is primarily concerned with transformations of entire histories, rather than of instantaneous states. We show that, (...) even in this context, a transformation generated by an arbitrary first-class constraint is also a gauge transformation, once the empirically observed electric field is correctly identified via its dynamical interactions with charge, and not simply given stipulatively as a certain combination of the potential and its derivatives. (shrink)

Recently two pairs of authors have aimed to vindicate the longstanding "orthodox" or conventional claim that a first-class constraint generates a gauge transformation in typical gauge theories such as electromagnetism, Yang-Mills and General Relativity, in response to the Lagrangian-equivalent reforming tradition, in particular Pitts, _Annals of Physics_ 2014. Both pairs emphasize the coherence of the extended Hamiltonian formalism against what they take to be core ideas in Pitts 2014, but both overlook Pitts 2014's sensitivity to ways that one might rescue (...) the claim in question, including an additive redefinition of the electrostatic potential. Hence the bulk of the paper is best interpreted as arguing that the longstanding claim about separate first-class constraints is _either false or trivial_---de-Ockhamization (using more when less suffices by splitting one quantity into the sum of two) being trivial. Unfortunately section 9 of Pitts 2014, a primarily verbal argument that plays no role in other works, is refuted. Pooley and Wallace's inverse Legendre transformation to de-Ockhamized electromagnetism with an additively redefined electrostatic potential, however, opens the door to a precisely analogous calculation introducing a photon mass, which shows that a _second-class primary_ constraint generates a 'gauge transformation' in the exactly same sense---a _reductio ad absurdum_ of the orthodox claim that a first-class constraint generates a gauge transformation _and a second-class constraint does not_. A _reductio_ using massive electromagnetism was presaged in Pitts 2014. Gauge freedom by de-Ockhamization does not require any constraints at all, first-class or second-class, because any dynamical variable in any Lagrangian can be de-Ockhamized into exhibiting trivial additive artificial gauge freedom by splitting one quantity into the sum of two. Physically interesting gauge freedom, however, is typically generated by a tuned sum of first-class constraints, not each first-class constraint alone. (shrink)

Part I: The Life of Cognitive Science:. William Bechtel, Adele Abrahamsen, and George Graham. Part II: Areas of Study in Cognitive Science:. 1. Analogy: Dedre Gentner. 2. Animal Cognition: Herbert L. Roitblat. 3. Attention: A.H.C. Van Der Heijden. 4. Brain Mapping: Jennifer Mundale. 5. Cognitive Anthropology: Charles W. Nuckolls. 6. Cognitive and Linguistic Development: Adele Abrahamsen. 7. Conceptual Change: Nancy J. Nersessian. 8. Conceptual Organization: Douglas Medin and Sandra R. Waxman. 9. Consciousness: Owen Flanagan. 10. Decision Making: J. Frank Yates (...) and Paul A. Estin. 11. Emotions: Paul E. Griffiths. 12. Imagery and Spatial Representation: Rita E. Anderson. 13. Language Evolution and Neuromechanisms: Terrence W. Deacon. 14. Language Processing: Kathryn Bock and Susan M. Garnsey. 15. Linguistics Theory: D. Terence Langendoen. 16. Machine Learning: Paul Thagard. 17. Memory: Henry L. Roediger III and Lyn M. Goff. 18. Perception: Cees Van Leeuwen. 19. Perception: Color: Austen Clark. 20. Problem Solving: Kevin Dunbar. 21. Reasoning: Lance J. Rips. 22. Social Cognition: Alan J. Lambert and Alison L. Chasteen. 23. Unconscious Intelligence: Rhianon Allen and Arthur S. Reber. 24. Understanding Texts: Art Graesser and Pam Tipping. 25. Word Meaning: Barbara C. Malt. Part III: Methodologies of Cognitive Science:. 26. Artificial Intelligence: Ron Sun. 27. Behavioral Experimentation: Alexander Pollatsek and Keith Rayner. 28. Cognitive Ethology: Marc Bekoff. 29. Deficits and Pathologies: Christopher D. Frith. 30. Ethnomethodology: Barry Saferstein. 31. Functional Analysis: Brian Macwhinney. 32. Neuroimaging: Randy L. Buckner and Steven E. Petersen. 33. Protocal Analysis: K. Anders Ericsson. 34. Single Neuron Electrophysiology: B. E. Stein, M.T. Wallace, and T.R. Stanford. 35. Structural Analysis: Robert Frank. Part IV: Stances in Cognitive Science:. 36. Case-based Reasoning: David B. Leake. 37. Cognitive Linguistics: Michael Tomasello. 38. Connectionism, Artificial Life, and Dynamical Systems: Jeffrey L. Elman. 39. Embodied, Situated, and Distributed Cognition: Andy Clark. 40. Mediated Action: James V. Wertsch. 41. Neurobiological Modeling: P. Read Montague and Peter Dayan. 42. Production Systems: Christian D. Schunn and David Klahr. Part V: Controversies in Cognitive Science:. 43. The Binding Problem: Valerie Gray Hardcastle. 44. Heuristics and Satisficing: Robert C. Richardson. 45. Innate Knowledge: Barbara Landau. 46. Innateness and Emergentism: Elizabeth Bates, Jeffrey L. Elman, Mark H. Johnson, Annette Karmiloff-Smith, Domenico Parisi, and Kim Plunkett. 47. Intentionality: Gilbert Harman. 48. Levels of Explanation and Cognition Architectures: Robert N. McCauley. 49. Modularity: Irene Appelbaum. 50. Representation and Computation: Robert S. Stufflebeam. 51. Representations: Dorrit Billman. 52. Rules: Terence Horgan and John Tienson. 53. Stage Theories Refuted: Donald G. Mackay. Part VI: Cognitive Science in the Real World:. 54. Education: John T. Bruer. 55. Ethics: Mark L. Johnson. 56. Everyday Life Environments: Alex Kirlik. 57. Institutions and Economics: Douglass C. North. 58. Legal Reasoning: Edwina L. Rissland. 59. Mental Retardation: Norman W. Bray, Kevin D. Reilly, Lisa F. Huffman, Lisa A. Grupe, Mark F. Villa, Kathryn L. Fletcher, and Vivek Anumolu. 60. Science: William F. Brewer and Punyashloke Mishra. Selective Biographies of Major Contributors to Cognitive Science: William Bechtel and Tadeusz Zawidzki. (shrink)

Brian Skyrms offers a fascinating demonstration of how fundamental signals are to our world. He uses various scientific tools to investigate how meaning and communication develop. Signals operate in networks of senders and receivers at all levels of life, transmitting and processing information. That is how humans and animals think and interact.

Brian Skyrms, author of the successful Evolution of the Social Contract has written a sequel. The book is a study of ideas of cooperation and collective action. The point of departure is a prototypical story found in Rousseau's A Discourse on Inequality. Rousseau contrasts the pay-off of hunting hare where the risk of non-cooperation is small but the reward is equally small, against the pay-off of hunting the stag where maximum cooperation is required but where the reward is so (...) much greater. Thus, rational agents are pulled in one direction by considerations of risk and in another by considerations of mutual benefit. Written with Skyrms's characteristic clarity and verve, this intriguing book will be eagerly sought out by students and professionals in philosophy, political science, economics, sociology and evolutionary biology. (shrink)

Almost every country today contains adherents of different religions and different secular conceptions of the good life. Is there any alternative to a power struggle among them, leading most probably to either civil war or repression? The argument of this book is that justice as impartiality offers a solution. According to the theory of justice as impartiality, principles of justice are those principles that provide a reasonable basis for the unforced assent of those subject to them. The object of this (...) book is to set the theory out, explain its rationale, and respond to a variety of criticism that have been made of it. As the second volume of his work-in-progress, A Treatise on Social Justice, this work lies at the heart of a thriving academic debate which the author has played a key role in shaping. (shrink)

Intuitively, Gettier cases are instances of justified true beliefs that are not cases of knowledge. Should we therefore conclude that knowledge is not justified true belief? Only if we have reason to trust intuition here. But intuitions are unreliable in a wide range of cases. And it can be argued that the Gettier intuitions have a greater resemblance to unreliable intuitions than to reliable intuitions. Whats distinctive about the faulty intuitions, I argue, is that respecting them would mean abandoning a (...) simple, systematic and largely successful theory in favour of a complicated, disjunctive and idiosyncratic theory. So maybe respecting the Gettier intuitions was the wrong reaction, we should instead have been explaining why we are all so easily misled by these kinds of cases. (shrink)

Brian Skyrms constructs a theory of "dynamic deliberation" and uses it to investigate rational decision-making in cases of strategic interaction. This illuminating book will be of great interest to all those in many disciplines who use decision theory and game theory to study human behavior and thought. Skyrms begins by discussing the Bayesian theory of individual rational decision and the classical theory of games, which at first glance seem antithetical in the criteria used for determining action. In his effort (...) to show how methods for dealing with information feedback can be productively combined, the author skillfully leads us through the mazes of equilibrium selection, the Nash equilibria for normal and extensive forms, structural stability, causal decision theory, dynamic probability, the revision of beliefs, and, finally, good habits for decision. The author provides many clarifying illustrations and a handy appendix called "Deliberational Dynamics on Your Personal Computer." His powerful model has important implications for understanding the rational origins of convention and the social contract, the logic of nuclear deterrence, the theory of good habits, and the varied strategies of political and economic behavior. (shrink)

Dogmatism is sometimes thought to be incompatible with Bayesian models of rational learning. I show that the best model for updating imprecise credences is compatible with dogmatism.

Conciliatory theories of disagreement face a revenge problem; they cannot be coherently believed by one who thinks they have peers who are not conciliationists. I argue that this is a deep problem for conciliationism.

Many writers have held that in his later work, David Lewis adopted a theory of predicate meaning such that the meaning of a predicate is the most natural property that is (mostly) consistent with the way the predicate is used. That orthodox interpretation is shared by both supporters and critics of Lewis's theory of meaning, but it has recently been strongly criticised by Wolfgang Schwarz. In this paper, I accept many of Schwarze's criticisms of the orthodox interpretation, and add some (...) more. But I also argue that the orthodox interpretation has a grain of truth in it, and seeing that helps us appreciate the strength of Lewis's late theory of meaning. (shrink)

Some instances of right and wrongdoing appear to be of a distinctly collective kind. When, for example, one group commits genocide against another, the genocide is collective in the sense that the wrongness of genocide seems morally distinct from the aggregation of individual murders that make up the genocide. The problem, which I refer to as the problem of collective wrongs, is that it is unclear how to assign blame for distinctly collective wrongdoing to individual contributors when none of those (...) individual contributors is guilty of the wrongdoing in question. I offer Christopher Kutz’s Complicity Principle as an attractive starting point for solving the problem, and then argue that the principle ought to be expanded to include a broader and more appropriate range of cases. The view I ultimately defend is that individuals are blameworthy for collective harms insofar as they knowingly participate in those harms, and that said individuals remain blameworthy regardless of whether they succeed in making a causal contribution to those harms. (shrink)

Suppose a rational agent S has some evidence E that bears on p, and on that basis makes a judgment about p. For simplicity, we’ll normally assume that she judges that p, though we’re also interested in cases where the agent makes other judgments, such as that p is probable, or that p is well-supported by the evidence. We’ll also assume, again for simplicity, that the agent knows that E is the basis for her judgment. Finally, we’ll assume that the (...) judgment is a rational one to make, though we won’t assume the agent knows this. Indeed, whether the agent can always know that she’s making a rational judgment when in fact she is will be of central importance in some of the debates that follow. (shrink)

This book uses computer modeling to investigate trends in what is published in leading philosophy journals over the last century and a half. The notable trends include the rise of realism from a fringe view to the mainstream metaphysical outlook, the increase in specialization, and the increasing depth of integration between philosophy and physical sciences. It also contains a guide to how to do similar investigations, and discussions of the strengths and weaknesses of the approach.

As anyone who has flown out of a cloud knows, the boundaries of a cloud are a lot less sharp up close than they can appear on the ground. Even when it seems clearly true that there is one, sharply bounded, cloud up there, really there are thousands of water droplets that are neither determinately part of the cloud, nor determinately outside it. Consider any object that consists of the core of the cloud, plus an arbitrary selection of these droplets. (...) It will look like a cloud, and circumstances permitting rain like a cloud, and generally has as good a claim to be a cloud as any other object in that part of the sky. But we cannot say every such object is a cloud, else there would be millions of clouds where it seemed like there was one. And what holds for clouds holds for anything whose boundaries look less clear the closer you look at it. And that includes just about every kind of object we normally think about, including humans. Although this seems to be a merely technical puzzle, even a triviality, a surprising range of proposed solutions has emerged, many of them mutually inconsistent. It is not even settled whether a solution should come from metaphysics, or from philosophy of language, or from logic. Here we survey the options, and provide several links to the many topics related to the Problem. (shrink)

Timothy Williamson has recently argued that few mental states are luminous , meaning that to be in that state is to be in a position to know that you are in the state. His argument rests on the plausible principle that beliefs only count as knowledge if they are safely true. That is, any belief that could easily have been false is not a piece of knowledge. I argue that the form of the safety rule Williamson uses is inappropriate, and (...) the correct safety rule might not conflict with luminosity. (shrink)

More and more people would like to migrate, but find that every state places barriers in their way. At the same time, most governments not only permit but court foreign investment. Can this difference between the treatment of people and the treatment of money be justified? This book asks this question from the point of view of five different ethical perspectives: liberal egalitarianism, libertarianism, Marxism, natural law and political realism. -- FROM BOOK JACKET.

Abstract Utterances of counterfactual conditionals are typically attended by the information that their antecedents are false. But there is as yet no account of the source of this information that is both detailed and complete. This paper describes the problem of counterfactual antecedent falsity and argues that the problem can be addressed by appeal to an adequate account of the presuppositions of various competing conditional constructions. It argues that indicative conditionals presuppose that their antecedents are epistemically possible, while subjunctive conditionals (...) bear no presupposition. Given this arrangement, utterance of the counterfactual results in an antipresupposition, that is, a scalar implicature generated from the presuppositions of competing alternatives rather than from the at-issue content of competing alternatives. The content of the antipresupposition is the negation of the presupposition of the competing indicative, i.e., that the antecedent of the conditional is known to be false by the speaker. (shrink)

What question are decision theorists trying to answer, and why is it worth trying to answer it? A lot of philosophers talk as if the aim of decision theory is to describe how we should make decisions, and the reason to do this is to help us make better decisions. I disagree on both fronts. The aim of the decision theory is to describe how a certain kind of idealised decider does in fact decide. And the reason to do this (...) is that this idealisation, like many other idealisations, helps generate explanations of real-world behaviour. We shouldn't do what these ideal deciders do, or try to be more like them, because a lot of what they do only makes sense because of the differences between us and them. Still, sometimes those differences are small enough that they can be ignored in explanations, and that's when decision theory is useful. (shrink)

Vagueness as Indeterminacy. I defend the traditional view that a vague term is one with an indeterminate denotation from a bevy of recent challenges.

What the world needs now is another theory of vagueness. Not because the old theories are useless. Quite the contrary, the old theories provide many of the materials we need to construct the truest theory of vagueness ever seen. The theory shall be similar in motivation to supervaluationism, but more akin to many-valued theories in conceptualisation. What I take from the many-valued theories is the idea that some sentences can be truer than others. But I say very different things to (...) the ordering over sentences this relation generates. I say it is not a linear ordering, so it cannot be represented by the real numbers. I also argue that since there is higher-order vagueness, any mapping between sentences and mathematical objects is bound to be inappropriate. This is no cause for regret; we can say all we want to say by using the comparative truer than without mapping it onto some mathematical objects. From supervaluationism I take the idea that we can keep classical logic without keeping the familiar bivalent semantics for classical logic. But my preservation of classical logic is more comprehensive than is normally permitted by supervaluationism, for I preserve classical inference rules as well as classical sequents. And I do this without relying on the concept of acceptable precisifications as an unexplained explainer. The world does not need another guide to varieties of theories of vagueness, especially since Timothy Williamson (1994) and Rosanna Keefe (2000) have already provided quite good guides. I assume throughout familiarity with popular theories of vagueness. (shrink)

We use data collected among Hadza hunter-gatherers between 2005 and 2009 to examine hypotheses about the causes and consequences of men’s foraging and food sharing. We find that Hadza men foraged for a range of food types, including fruit, honey, small animals, and large game. Large game were shared not like common goods, but in ways that significantly advantaged producers’ households. Food sharing and consumption data show that men channeled the foods they produced to their wives, children, and their consanguineal (...) and affinal kin living in other households. On average, single men brought food to camp on 28% of days, married men without children at home on 31% of days, and married men with children at home on 42% of days. Married men brought fruit, the least widely shared resource, to camp significantly more often than single men. A model of the relationship between hunting success and household food consumption indicates that the best hunters provided 3–4 times the amount of food to their families than median or poor hunters. These new data fill important gaps in our knowledge of the subsistence economy of the Hadza and uphold predictions derived from the household and kin provisioning hypotheses. Key evidence and assumptions backing prior claims that Hadza hunting is largely a form of status competition were not replicated in our study. In light of this, family provisioning is a more viable explanation for why good hunters are preferred as husbands and have higher fertility than others. (shrink)

This paper argues that "moral luck", understood as a susceptibility of moral desert to lucky or unlucky outcomes, does not exist. The argument turns on the claim that epistemic inquiry is an indissoluble part of moral responsibility, and that judgment on the moral decision making of others should and can adjust for this fact; test cases which aim to isolate moral dilemmas from epistemic consideration misrepresent our moral experience. If the phenomena believed by some philosophers to exemplify the need to (...) admit moral luck as part of their explanation are analysed in the light of this insight, the case for "moral luck" dissolves. (shrink)

This paper contributes to the project of articulating and defending the supra-Bayesian approach to judgment aggregation. I discuss three cases where a person is disposed to defer to two different experts, and ask how they should respond when they learn about the opinion of each. The guiding principles are that this learning should go by conditionalisation, and that they should aim to update on the evidence that the expert had updated on. But this doesn’t settle how the update on pairs (...) of experts should go, because we also need to know how the experts are related. I work through three examples showing how the results change given different prior beliefs about this relationship. (shrink)

Uncertainty plays an important role in The General Theory, particularly in the theory of interest rates. Keynes did not provide a theory of uncertainty, but he did make some enlightening remarks about the direction he thought such a theory should take. I argue that some modern innovations in the theory of probability allow us to build a theory which captures these Keynesian insights. If this is the right theory, however, uncertainty cannot carry its weight in Keynes’s arguments. This does not (...) mean that the conclusions of these arguments are necessarily mistaken; in their best formulation they may succeed with merely an appeal to risk. (shrink)

This paper contributes to the underdeveloped field of experimental philosophy of science. We examine variability in the philosophical views of scientists. Using data from Toolbox Dialogue Initiative, we analyze scientists’ responses to prompts on philosophical issues (methodology, confirmation, values, reality, reductionism, and motivation for scientific research) to assess variance in the philosophical views of physical scientists, life scientists, and social and behavioral scientists. We find six prompts about which differences arose, with several more that look promising for future research. We (...) then evaluate the difference between the natural and social sciences and the challenge of interdisciplinary integration across scientific branches. (shrink)

Orthodox Bayesian decision theory requires an agent’s beliefs representable by a real-valued function, ideally a probability function. Many theorists have argued this is too restrictive; it can be perfectly reasonable to have indeterminate degrees of belief. So doxastic states are ideally representable by a set of probability functions. One consequence of this is that the expected value of a gamble will be imprecise. This paper looks at the attempts to extend Bayesian decision theory to deal with such cases, and concludes (...) that all proposals advanced thus far have been incoherent. A more modest, but coherent, alternative is proposed. Keywords: Imprecise probabilities, Arrow’s theorem. (shrink)

A common view among nontheists combines the de jure objection that theism is epistemically unacceptable with agnosticism about the de facto objection that theism is false. Following Plantinga, we can call this a “proper” de jure objection—a de jure objection that does not depend on any de facto objection. In his Warranted Christian Belief, Plantinga has produced a general argument against all proper de jure objections. Here I first show that this argument is logically fallacious (it makes subtle probabilistic fallacies (...) disguised by scope ambiguities), and proceed to lay the groundwork for the construction of actual proper de jure objections. (shrink)

The central thesis of this paper is that fake news and related phenomena serve as defeaters for knowledge transmission via journalistic channels. This explains how they pose a threat to democracy; and it points the way to determining how to address this threat. Democracy is both intrinsically and instrumentally good provided the electorate has knowledge (however partial and distributed) of the common good and the means of achieving it. Since journalism provides such knowledge, those who value democracy have a reason (...) to protect it. Hostile agents, however, can undermine both the effectiveness of democratic decision-making and faith in democracy itself, by deliberately promulgating fake news and hyper-partisan views; moreover, these effects can come about unintentionally on social media. I conclude that we may need to change, not just the way we process information online, but also the informational environment in which we operate. (shrink)

Safety-based theories of knowledge face a difficulty surrounding necessary truths: no subject could have easily falsely believed such a proposition. Failing to predict that ill-grounded beliefs in such propositions do not constitute knowledge, standard safety theories are therefore less informative than desired. Some have suggested that the subjects at issue could easily have believed some related false proposition; but they have given no indication as to what makes a proposition related. I suggest a solution to this problem: a belief is (...) safe iff its subject could not easily have believed a false answer to the same question. (shrink)

Brian Skyrms applies adaptive dynamics (of cultural evolution and individual learning) to social theory, investigating altruism, spite, fairness, trust, division of labor, and signaling. Correlation is seen to be fundamental. Spontaneous emergence of social structure and of signaling systems are examined in the context of learning dynamics.

Applying good inductive rules inside the scope of suppositions leads to implausible results. I argue it is a mistake to think that inductive rules of inference behave anything like 'inference rules' in natural deduction systems. And this implies that it isn't always true that good arguments can be run 'off-line' to gain a priori knowledge of conditional conclusions.

I argue with my friends a lot. That is, I offer them reasons to believe all sorts of philosophical conclusions. Sadly, despite the quality of my arguments, and despite their apparent intelligence, they don’t always agree. They keep insisting on principles in the face of my wittier and wittier counterexamples, and they keep offering their own dull alleged counterexamples to my clever principles. What is a philosopher to do in these circumstances? (And I don’t mean get better friends.) One popular (...) answer these days is that I should, to some extent, defer to my friends. If I look at a batch of reasons and conclude p, and my equally talented friend reaches an incompatible conclusion q, I should revise my opinion so I’m now undecided between p and q. I should, in the preferred lingo, assign equal weight to my view as to theirs. This is despite the fact that I’ve looked at their reasons for concluding q and found them wanting. If I hadn’t, I would have already concluded q. The mere fact that a friend (from now on I’ll leave off the qualifier ‘equally talented and informed’, since all my friends satisfy that) reaches a contrary opinion should be reason to move me. Such a position is defended by Richard Feldman (2006a, 2006b), David Christensen (2007) and Adam Elga (forthcoming). This equal weight view, hereafter EW, is itself a philosophical position. And while some of my friends believe it, some of my friends do not. (Nor, I should add for your benefit, do I.) This raises an odd little dilemma. If EW is correct, then the fact that my friends disagree about it means that I shouldn’t be particularly confident that it is true, since EW says that I shouldn’t be too confident about any position on which my friends disagree. But, as I’ll argue below, to consistently implement EW, I have to be maximally confident that it is true. So to accept EW, I have to inconsistently both be very confident that it is true and not very confident that it is true. This seems like a problem, and a reason to not accept EW.. (shrink)

Assume, for fun, that temporal parts theory is true, and that some kind of modal realism (perhaps based on ersatz worlds) is true. Within this grand metaphysical picture, what are the ordinary objects? Do they have many temporal parts, or just one? Do they have many modal parts, or just one? I survey the issues involved in answering this question, including the problem of temporary intrinsics, the problem of the many, Kripke's objections to counterpart theory and quantifier domain restrictions.

If we add as an extra premise that the agent does know H, then it is possible for her to know E — H, we get the conclusion that the agent does not really know H. But even without that closure premise, or something like it, the conclusion seems quite dramatic. One possible response to the argument, floated by both Descartes and Hume, is to accept the conclusion and embrace scepticism. We cannot know anything that goes beyond our evidence, so (...) we do not know very much at all. This is a remarkably sceptical conclusion, so we should resist it if at all possible. A more modern response, associated with externalists like John McDowell and Timothy Williamson, is to accept the conclusion but deny it is as sceptical as it first appears. The Humean argument, even if it works, only shows that our evidence and our knowledge are more closely linked than we might have thought. Perhaps that’s true because we have a lot of evidence, not because we have very little knowledge. There’s something right about this response I think. We have more evidence than Descartes or Hume thought we had. But I think we still need the idea of ampliative knowledge. It stretches the concept of evidence to breaking point to suggest that all of our knowledge, including knowledge about the future, is part of our evidence. So the conclusion really is unacceptable. Or, at least, I think we should try to see what an epistemology that rejects the conclusion looks like. (shrink)