Since 1970, a United States prosecutor can prove perjury without specifying which statement is perjurious. A bold prosecutor could concede ignorance of which statement is false. A bolder prosecutor could further concede that the witness himself does not know. The boldest prosecutor could concede there is no specific lie. Instead of there being a statement that is intrinsically perjurious, the perjury is relational. Just as two statements can be inconsistent without either being inconsistent, two statements can be perjurious without either (...) being perjurious. These consequences are reconciled with the generalisation that all perjury involves lying. Corollaries about culpability are drawn from the phenomenon of nonspecific perjury. The reasoning is generalised to other forms of illegal lying. (shrink)

Roy Sorenson offers a unique exploration of an ancient problem: vagueness. Did Buddha become a fat man in one second? Is there a tallest short giraffe? According to Sorenson's epistemicist approach, the answers are yes! Although vagueness abounds in the way the world is divided, Sorenson argues that the divisions are sharp; yet we often do not know where they are. Written in Sorenson'e usual inventive and amusing style, this book offers original insight on language and logic, the way world (...) is, and our understanding of it. (shrink)

Can merely thinking about an imaginary situation provide evidence for how the world actually is--or how it ought to be? In this lively book, Roy A. Sorensen addresses this question with an analysis of a wide variety of thought experiments ranging from aesthetics to zoology. Presenting the first general theory of thought experiment, he sets it within an evolutionary framework and integrates recent advances in experimental psychology and the history of science, with special emphasis on Ernst Mach and Thomas (...) Kuhn. Sorensen explores what thought experiments are, how they work, and what their virtues and vices are. In his view, philosophy differs from science in degree, but not in kind. For this reason, he claims, it is possible to understand philosophical thought experiments by concentrating on their resemblance to scientific relatives. Sorensen assesses the hazards of thought experiments and grants that there are interesting ways in which the method leads us astray, but attacks most scepticism about thought experiments as arbitrary. He maintains that they should be used--as they generally are--as part of a diversified portfolio of techniques, creating a network of cross-checks that make for impressive reliability. (shrink)

Sorensen here offers a unified solution to a large family of philosophical puzzles and paradoxes through a study of "blindspots": consistent propositions that cannot be rationally accepted by certain individuals even though they might by true.

Do we need light to see? I argue that the black experience of a man in a perfectly dark cave is a representation of an absence of light, not an absence of representation. There is certainly a difference between his perceptual knowledge and that of his blind companion. Only the sighted man can tell whether the cave is dark just by looking. But perhaps he is merely inferring darkness from his failure to see. To get an unambiguous answer, I switch (...) the focus from perceptual knowledge to non-epistemic seeing. My conclusion is that we see even in the limiting case of absolute darkness - regardless of whether we believe we are seeing. We see little of pratical interest. But in terms of basic information, we see about as much as we do when the lights are on. Depending on what has gone before and after, we may even see ordinary objects. (shrink)

Sorensen presents a general theory of thought experiments: what they are, how they work, what are their virtues and vices. On Sorensen's view, philosophy differs from science in degree, but not in kind. For this reason, he claims, it is possible to understand philosophical thought experiments by concentrating on their resemblance to scientific relatives. Lessons learned about scientific experimentation carry over to thought experiment, and vice versa. Sorensen also assesses the hazards and pseudo-hazards of thought experiments. Although (...) he grants that there are interesting ways in which the method leads us astray, he attacks most scepticism about thought experiments as arbitrary. They should be used, he says, as they generally are used--as part of a diversified portfolio of techniques. All of these devices are individually susceptible to abuse, fallacy, and error. Collectively, however, they provide a network of cross-checks that make for impressive reliability. (shrink)

The eclipse riddle -- Seeing surfaces -- The disappearing act -- Spinning shadows -- Berkeley's shadow -- Para-reflections -- Para-refractions : shadowgrams and the black drop -- Goethe's colored shadows -- Filtows -- Holes in the light -- Black and blue -- Seeing in black and white -- We see in the dark -- Hearing silence.

In this book, Sorensen presents the first general theory of the thought experiment. He analyses a wide variety of thought experiments, ranging from aesthetics to zoology, and explores what thought experiments are, how they work, and what their positive and negative aspects are. Sorensen also sets his theory within an evolutionary framework and integrates recent advances in experimental psychology and the history of science.

Surprisingly, the fact that the speaker is lying is sometimes common knowledge between everyone involved. Strangely, we condemn these bald-faced lies more severely than disguised lies. The wrongness of lying springs from the intent to deceive – just the feature missing in the case of bald-faced lies. These puzzling lies arise systematically when assertions are forced. Intellectual duress helps to explain another type of non-deceptive false assertion : lying to yourself. In the end, I conclude that the apparent intensity of (...) our disapproval of non-deceptive lies is a rhetorical illusion. (shrink)

This chapter focuses on the property that excited Kuhn's interest in thought experiments: conflict vagueness. This property often generates inconsistent beliefs but is not itself inconsistency. Although it is absent from most thought experiments, a substantial portion of the most provocative thought experiments do spring from this species of vagueness; for they motivate conceptual reform by touching a nerve of indeterminacy. Hence, study of conflict vagueness reveals the ways thought experiments restructure our conceptual scheme.

This chapter examines the hazards and pseudohazards of thought experiment. It attacks most skepticism about thought experiment as arbitrary. It argues that once the standards that are customary for compasses, stethoscopes, and other testing devices are applied, thought experiments measure up. They should be used as part of a diversified portfolio of techniques. Although all these devices are individually susceptible to abuse, fallacy, and error, they provide a network of cross-checks that make for impressive collective reliability.

This chapter focuses on Thomas Kuhn's account of thought experiments. It begins with what Kuhn takes to be the smart talk about thought experiments. It then details Kuhn's amendments to this view and raises objections, most of which are directed against the notion of local incoherence. Finally, Kuhn's error is reconstructed in order to salvage the considerable insight that it contains.

This chapter illustrates the power of thought experiments by assembling influential thought experiments from the history of science. It lays out the book's plan to understand philosophical thought experiments by concentrating on their resemblance to scientific relatives. Points of difference between philosophical and scientific thought experiments give a preview of obstacles that must be overcome in the course of the campaign. Naive and sophisticated reservations about the philosophical cases are registered for the same purpose.

This chapter focuses on armchair inquiry. Thought experiment has the feel of clairvoyance, thus eliciting awe in some and suspicion in others. But the wonder of thought experiment is just a special case of our vague puzzlement about how a question could be answered by merely thinking. There is no mystery when investigators look, measure, and manipulate. Their answers come from the news borne by observation and experiment. But if you just ponder, then the information you have leaving the armchair (...) is the same as the information you had when you sat down. It is argued that part of our wonder is based on a modal fallacy. The theories of armchair inquiry that promise answers to the legitimate portion of our wonder are surveyed. Finally, a cleansing model of rationality that sets the stage for a detailed analysis of how thought experiments work is developed. (shrink)

A Brief History of the Paradox is the first narrative history of paradoxes. Sorenson draws us deep inside the tangles of riddles, paradoxes and conundrums by answering the questions which are seemingly unanswerable. Can God create a stone too heavy for him to lift? Can time have a beginning? Which came first, the chicken or the egg? Filled with illuminating anecdotes, A Brief History of the Paradox is vividly written and will appeal to anyone who finds trying to answer unanswerable (...) questions a paradoxically pleasant endeavour. (shrink)

The aim of this paper is to show how thought experiments help us learn about laws. After providing examples of this kind of nomic illumination in the first section, I canvass explanations of our modal knowledge and opt for an evolutionary account. The basic application is that the laws of nature have led us to develop rough and ready intuitions of physical possibility which are then exploited by thought experimenters to reveal some of the very laws responsible for those intuitions. (...) The good news is that natural selection ensures a degree of reliability for the intuitions. The bad news is that the evolutionary account seems to limit the range of reliable thought experiment to highly practical and concrete contexts. In the fifth section, I provide reasons for thinking that we are not as slavishly limited as a pessimistic construal of natural selection suggests. Nevertheless, I promote the idea that biology is a promising source of predictions and diagnoses of thought experiment failures. (shrink)

Can God create a stone too heavy for him to lift? Can time have a beginning? Which came first, the chicken or the egg? Riddles, paradoxes, conundrums--for millennia the human mind has found such knotty logical problems both perplexing and irresistible. Now Roy Sorensen offers the first narrative history of paradoxes, a fascinating and eye-opening account that extends from the ancient Greeks, through the Middle Ages, the Enlightenment, and into the twentieth century. When Augustine asked what God was doing (...) before He made the world, he was told: "Preparing hell for people who ask questions like that." A Brief History of the Paradox takes a close look at "questions like that" and the philosophers who have asked them, beginning with the folk riddles that inspired Anaximander to erect the first metaphysical system and ending with such thinkers as Lewis Carroll, Ludwig Wittgenstein, and W.V. Quine. Organized chronologically, the book is divided into twenty-four chapters, each of which pairs a philosopher with a major paradox, allowing for extended consideration and putting a human face on the strategies that have been taken toward these puzzles. Readers get to follow the minds of Zeno, Socrates, Aquinas, Ockham, Pascal, Kant, Hegel, and many other major philosophers deep inside the tangles of paradox, looking for, and sometimes finding, a way out. Filled with illuminating anecdotes and vividly written, A Brief History of the Paradox will appeal to anyone who finds trying to answer unanswerable questions a paradoxically pleasant endeavor. (shrink)

Seizing the opportunity to apply what they had learned, the students declared a cheating competition. Outspoken participants (future lawyers, politicians, and captains of industry) bragged about their ruses. But to their chagrin, an ethics student prevailed.

The argument proceeds by exploiting the gradually decreasing vagueness of a certain sequence of predicates. the vagueness of 'vague' is then used to show that the thesis that all vague predicates are incoherent is self-defeating. a second casualty is the view that the probems of vagueness can be avoided by restricting the scope of logic to nonvague predicates.

Sorensen provides a panoramic view of paradoxes of theoretical and practical rationality. These puzzles are organized as apparent counterexamples to attractive principles such as the principle of charity, the transitivity of preferences, and the principle that we should maximize expected utility. The following paradoxes are discussed: fearing fictions, the surprise test paradox, Pascal’s Wager, Pollock’s Ever Better wine, Newcomb’s problem, the iterated prisoner’s dilemma, Kavka’s paradoxes of deterrence, backward inductions, the bottle imp, the preface paradox, Moore’s problem, Buridan’s ass, (...) Condorcet’s paradox of cyclical majorities, the St. Petersburg paradox, weakness of will, the Ellsberg paradox, Allais’s paradox, and Peter Cave’s puzzle of self-fulfilling beliefs. (shrink)

in Sounds and Perception: New Philosophical Essays, ed. by Matthew Nudds and Casey O’Callaghan (Oxford University Press, forthcoming in 2008).

Prize: One hundred dollars to the first person who identifies a picture of a logical impossibility. I may be willing to pay more for the painting itself. This finder’s fee is simply for pointing out the picture. Let me explain more precisely what I seek.

To understand lying, we naturally focus on small scale lies involving one speaker, one listener, one assertion. This methodology confers artificial plausibility upon the requirement that liars intend to deceive. For it excludes principal-agent conflicts that emerge from linguistic division of labor. When an employee lies for her boss, she need not inherit his motive to deceive. She displays loyalty even if her lie does not deceive. Focus on a single lie in isolation also blinds us to tactical deceptions such (...) as telling a lie which is intended to be caught to advance another lie. Many of these complexities arise from situations that approximate common knowledge without quite crystallizing into this uniform transparency. (shrink)

You face two buttons. Pushing one will destroy Greensboro. Pushing the other will save it. There is no way for you to know which button saves and which destroys. What ought you to do? Answer: You ought to make the correct guess and push the button that saves Greensboro. Second question: Do you have an obligation to push the correct button?

The aim of this paper is to show how thought experiments help us learn about laws. After providing examples of this kind of nomic illumination in the first section, I canvass explanations of our modal knowledge and opt for an evolutionary account. The basic application is that the laws of nature have led us to develop rough and ready intuitions of physical possibility which are then exploited by thought experimenters to reveal some of the very laws responsible for those intuitions. (...) The good news is that natural selection ensures a degree of reliability for the intuitions. The bad news is that the evolutionary account seems to limit the range of reliable thought experiment to highly practical and concrete contexts. In the fifth section, I provide reasons for thinking that we are not as slavishly limited as a pessimistic construal of natural selection suggests. Nevertheless, I promote the idea that biology is a promising source of predictions and diagnoses of thought experiment failures. (shrink)

An entertaining history of the idea of nothing - including absences, omissions, and shadows - from the Ancient Greeks through the 20th century How can nothing cause something? The absence of something might seem to indicate a null or a void, an emptiness as ineffectual as a shadow. In fact, 'nothing' is one of the most powerful ideas the human mind has ever conceived. This short and entertaining book by Roy Sorensen is a lively tour of the history and (...) philosophy of nothing, explaining how various thinkers throughout history have conceived and grappled with the mysterious power of absence -- and how these ideas about shadows, gaps, and holes have in turned played a very positive role in the development of some of humankind's most important ideas. Filled with Sorensen's characteristically entertaining mix of anecdotes, puzzles, curiosities, and philosophical speculation, the book is ordered chronologically, starting with the Taoists, the Buddhists, and the ancient Greeks, moving forward to the middle ages and the early modern period, then up to the existentialists and present day philosophy. The result is a diverting tour through the history of human thought as seen from a novel and unusual perspective. (shrink)

The vanishing point is a representational gap that organizes the visual field. Study of this singularity revolutionized art in the fifteenth century. Further reflection on the vanishing point invites the conjecture that the self is an absence. This paper opens with perceptual peculiarities of the vanishing point and closes with the metaphysics of personal identity.

This is a defense and extension of Stephen Yablo's claim that self-reference is completely inessential to the liar paradox. An infinite sequence of sentences of the form 'None of these subsequent sentences are true' generates the same instability in assigning truth values. I argue Yablo's technique of substituting infinity for self-reference applies to all so-called 'self-referential' paradoxes. A representative sample is provided which includes counterparts of the preface paradox, Pseudo-Scotus's validity paradox, the Knower, and other enigmas of the genre. I (...) rebut objections that Yablo's paradox is not a genuine liar by constructing a sequence of liars that blend into Yablo's paradox. I rebut objections that Yablo's liar has hidden self-reference with a distinction between attributive and referential self-reference and appeals to Gregory Chaitin's algorithmic information theory. The paper concludes with comments on the mystique of self-reference. (shrink)

In ‘Epistemic Modals’ (2007), Seth Yalcin proposes Stalnaker-style semantics for epistemic possibility. He is inspired by John MacFarlane’s ingenious defence of relativism, in which claims of epistemic possibility are made rigidly from the perspective of the assessor’s actual stock of information (rather than from the speaker’s knowledge base or that of his audience or community). The innovations of MacFarlane and Yalcin independently reinforce the modal collapse espoused by Jaakko Hintikka in his 1962 epistemic logic (which relied on the implausible KK (...) principle and heavy idealizations). I respond to this new challenge with fresh objections to the underlying S4 equivalence: p p . I also propose counter-analyses of the intriguing data which Yalcin cites in support of his new semantics. A key collateral motivation for this defence of irredundant iterations is to ward off a threat to higher order vagueness. (shrink)

Islamic building codes require mosques to face Mecca. The further Islam spreads, the more apt are believers to fall into a quandary. X faces Y only when the front of X is closer to Y than any other side of X. So the front of the mosque should be oriented along a shortest path to Mecca. Which way is that? Does the path to Mecca tunnel through the earth? Or does the path follow the surface of the earth?

Stepping into the other guy’s shoes works best when you resemble him. After all, the procedure is to use yourself as a model: in goes hypothetical beliefs and desires, out comes hypothetical actions and revised beliefs and desires. If you are structurally analogous to the empathee, then accurate inputs generate accurate outputs---just as with any other simulation. The greater the degree of isomorphism, the more dependable and precise the results. This sensitivity to degrees of resemblance suggests that the method of (...) empathy works best for average people. The advantage of being a small but representative sample of the population will create a bootstrap effect. For as average people prosper, there will be more average descendants and so the degree of resemblance in subsequent generations will snowball. Each increment in like-mindedness further enhances the reliability and validity of mental simulation. With each circuit along the spiral, there is tighter and tighter bunching and hence further empowerment of empathy. The method is self-strengthening and eventually molds a population of hyper-similar individuals---which partly solves the problem of other minds. (shrink)

Suppose you have an infinite past. If you had banked the spare dollar you have always had, then the interest would have made you rich by now. Your procrastination is inexcusable. But what should you have done? At any time at which you invest the dollar you would regret not investing it earlier. Satisficers can solve prospective puzzles involving infinite choice but cannot solve this retrospective puzzle about regret. A moral version of the puzzle suggests that there can be inevitable (...) moral failure. It does so without appeal to moral luck, moral dilemmas or original sin. (shrink)

Todd’s quip absurdly implies he knew that 30 carats is the threshold for vulgarity. But most philosophers think stopping here misses the root of the joke. They think there is a more fundamental absurdity; that it is even possible for a single carat to make the difference between a vulgar ring and a non-vulgar ring. We epistemicists defend the possibility.

The vanishing point is a representational gap that organizes the visual field. Study of this singularity revolutionized art in the fifteenth century. Further reflection on the vanishing point invites the conjecture that the self is an absence. This paper opens with perceptual peculiarities of the vanishing point and closes with the metaphysics of personal identity.

In the twentieth century, philosophers tackled many of the philosophical problems of previous generations by dissolving them--attacking them as linguistic illusions and showing that the problems, when closely inspected, were not problems at all. Roy A. Sorensen takes the most important and interesting examples from one hundred years of analytic philosophy to consolidate a different theory of dissolution. Pseudo-Problems offers a fascinating alternative history of twentieth century analytic philosophy. It seeks to outline a unified account of dissolution that can (...) consolidate the piecemeal insights of analytic philosophers. An accessible account of questionable questions, the book represents an important contribution to the debates about creativity and problem solving. (shrink)

Drawing inspiration from the ethical pluralism of G. E. Moore's Principia Ethica, I contend that one empty world can be morally better than another. By ?empty? I mean that it is devoid of concrete entities (things that have a position in space or time). These worlds have no thickets or thimbles, no thinkers, no thoughts. Infinitely many of these worlds have laws of nature, abstract entities, and perhaps, space and time. These non-concrete differences are enough to make some of them (...) better than others. 1I thank Walter Sinnott-Armstrong, John Carroll, and Gideon Rosen for their comments and suggestions. (shrink)