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)

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 _Plato on Democracy and Political technē_ Anders Dahl Sørensen offers an in-depth investigation of Plato’s discussions of democracy’s ‘epistemic potential’, arguing that this question is far more central to his political thought than is usually assumed.

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)

In ”Formal Problems about Knowledge,” Roy Sorensen examines epistemological issues that have logical aspects. He uses Fitch's proof for unknowables and the surprise test paradox to illustrate the hopes of the modal logicians who developed epistemic logic, and he considers the epistemology of proof with the help of the knower paradox. One solution to this paradox is that knowledge is not closed under deduction. Sorensen reviews the broader history of this maneuver along with the relevant alternatives model of knowledge which (...) assumes that ”know” is an absolute term like ”flat.” Sorensen argues that the difference between epistemic absolute terms and extensional absolute terms gives rise to an asymmetry that undermines recent claims that there is a structural parallel between the supervaluational and epistemicist theories of vagueness, and he suggests that we have overestimated the ability of logical demonstration to produce knowledge. (shrink)

A Cabinet of Philosophical Curiosities is a collection of puzzles, paradoxes, riddles, and miscellaneous logic problems. Depending on taste, one can partake of a puzzle, a poem, a proof, or a pun.

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?

For most of his career, Kant accepts Augustine's requirement that lying requires an intention to deceive. However, he eventually converts to Aquinas, following him in rejecting this requirement in favor of Aristotle's teleological conception of lying. This change of view amounts to an improvement, for it makes room for the possibility of lying to an omniscient being—and such lies, we argue, are indeed possible. We accompany these historical and philosophical theses with a biographical thesis taking the form of the following (...) story. Kant believed that in his youth he had lied to God, largely because of his religious training. He adopted policies designed to help him resist the habit of lying to God. However, this program conflicted with his desire to lead a well‐rounded life as a public intellectual. This worldly ambition led him to forego the Quaker solution to the problem of lying to God: refuse to swear any oath to God, avoid set prayers and hymns, decline offers of intercession by clergy. Kant's worldly compromise served him well, but as he entered his twilight years, he came to worry that his only surviving argument for theism—the moral argument—might constitute a relapse into the vice of lying to God. (shrink)

Do not pass by my epitaph, Wayfarer, but when you have stopped, hear and learn, then depart. There is no boat, To carry you to Hades, No ferryman Charon, No judge Aeacus, No Dog Cerberus. All of us below have become bones and ashes. Truly, I have nothing more to tell you. So depart, wayfarer, Lest dead though I am I seem to you to be a teller of vain tales.

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.

Verisimilitude has the potential to deepen the understanding of mathematical progress, the principle of charity, and the psychology of regret. One obstacle is the widely held belief that two statements can vary in truthlikeness only if they vary in what they entail. This obstacle is removed with four types of counterexamples. The first concerns necessarily coextensive measurements that differ only with respect to their units (specifically length, area, and volume). The second class ofcounterexamples is composed of mathematical falsehoods. The third (...) class features inconsistent scientific theories. The fourth class of cases features statements that are instructive but meaningless. (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)

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.

THE PURPOSE OF THIS ARTICLE IS TO SHOW HOW HUME’S SCEPTICISM ABOUT MIRACLES GENERATES "EPISTEMOLOGICAL" SCEPTICISM ABOUT TIME TRAVEL. SO THE PRIMARY QUESTION RAISED HERE IS "CAN ONE KNOW THAT TIME TRAVEL HAS OCCURED?" RATHER THAN "CAN TIME TRAVEL OCCUR?" I ARGUE THAT ATTEMPTS TO SHOW THE EXISTENCE OF TIME TRAVEL WOULD FACE THE SAME METHODOLOGICAL PROBLEMS AS THE ONES CONFRONTING ATTEMPTS TO DEMONSTRATE THE EXISTENCE OF PARANORMAL EVENTS. SINCE HUMEAN SCEPTICISM EXTENDS TO THE STUDY OF PARANORMAL EVENTS (PARAPSYCHOLOGY), HUMEANS (...) ARE COMMITTED TO SCEPTICISM ABOUT THE STUDY OF TIME TRAVEL ("PARAHISTORY"). (shrink)

The gestational surrogate – and her economic and educational vulnerability in particular – is the focus of many of the most persistent worries about paid surrogacy. Those who employ her, and those who broker and organize her services, usually have an advantage over her in resources and information. That asymmetry exposes her to the possibility of exploitation and abuse. Accordingly, some argue for banning paid surrogacy. Others defend legal permission on grounds of surrogate autonomy, but often retain concerns about the (...) surrogate. In response to the dilemma of a ban versus bald permission, we propose a 'soft law' approach: states should require several hours of education of surrogates – education aimed at informing and enhancing surrogate autonomy. (shrink)

If a spinning sphere casts a shadow, does the shadow also spin? This riddle is the point of departure for an investigation into the nature of shadow movement. A general theory of motion will encompass all moving things, not just physical objects. Ultimately, I argue that round shadows do indeed spin. Shadows are followers of the objects that cast them. Parts of the shadow correspond to parts of the leader, so motion of the caster's parts accounts for motions of the (...) shadow's parts. I conclude with a discussion of how the dynamic aspects of shadows impose subtle constraints on other puzzles about shadows. (shrink)

We review the use of introspective and phenomenological methods in experimental settings. We distinguish different senses of introspection, and further distinguish phenomenological method from introspectionist approaches. Two ways of using phenomenology in experimental procedures are identified: first, the neurophenomenological method, proposed by Varela, involves the training of experimental subjects. This approach has been directly and productively incorporated into the protocol of experiments on perception. A second approach may have wider application and does not involve training experimental subjects in phenomenological method. (...) It requires front-loading phenomenological insights into experimental design. A number of experiments employing this approach are reviewed. We conclude with a discussion of the implications for both the cognitive sciences and phenomenology. (shrink)

Both individuals with diagnosed with Autism Spectrum Disorder and individuals high in psychopathic traits show reduced susceptibility to contagious yawning; that is, yawning after seeing or hearing another person yawn. Yet it is unclear whether the same underlying processes are responsible for the relationship between reduced contagion and these very different types of clinical traits. College Students watched videos of individuals yawning or scratching while their eye movements were tracked. They completed the Interpersonal Reactivity Index, the Autism-Spectrum Quotient, the Psychopathy (...) Personality Inventory-Revised, and the Adolescent and Adult Sensory Processing Disorder Checklist. Both psychopathic traits and autistic traits showed an inverse relationship to contagious yawning, consistent with previous research. However, the relationship between autistic traits and contagious yawning was moderated by eye gaze. Furthermore, participants high in autistic traits showed typical levels of contagious itching whereas adults high in psychopathic traits showed diminished itch contagion. Finally, only psychopathic traits were associated with lower overall levels of empathy. The findings imply that the underlying processes contributing to the disruptions in contagious yawning amongst individuals high in autistic vs. psychopathic traits are distinct. In contrast to adults high in psychopathic traits, diminished contagion may appear amongst people with high levels of autistic traits secondary to diminished attention to the faces of others, and in the absence of a background deficit in emotional empathy. (shrink)

Charitable interpreters of David Hume set aside his sprinkles of piety. Better to read him as lying than as clumsily inconsistent. We argue that the attribution of lies can pay dividends in historical scholarship no matter how strongly the theorist condemns lying. Accordingly, we show that our approach works even with one of the strongest condemners of lying: Immanuel Kant. We argue that Kant lied in his scholarly work and even in the first Critique. And we defend the claim that (...) this lie attribution, strange as it may sound, amounts to a kind of scholarly charity. (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.

Social studies of science and technology are dominated by action and macro approaches. This has led to a neglect of institutions and institutional arrangements at the meso level, which are important, in particular to the student of technology. The transfer of concepts and methods from social studies of science to technology studies has conserved this lack of concern with the meso level. This article suggests a more critical evaluation of this transfer, along with a review of the now popular assumption (...) of a high degree of similarity between science and technology. Two case studies show how meso-level considerations are important to an understanding of the nature of technological innovation and illustrate the lack of similarity between scientific and technological development. (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)

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)

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.

Friesen's comparison between classroom practices and digital dissection carries the flaws of treating the digital and non-digital learning materials differently when comparing. This reply paper argues for a symmetric comparison through a focus on the way in which comparability between digital and non-digital learning materials is established by the researcher. It is suggested that such comparison might have brought about a result more favorable for digital technology.

Cattle production has the potential of being an important component of sustainable agriculture globally. The ability to transform feed not suitable for humans into high-quality food will be of great importance in the long-term for feeding a growing population. Other aspects such as preservation of landscape values and maintenance of rural communities are highly appreciated values, especially in the industrialized part of the world.To exploit the sustainable potential of cattle production systems, problems of pollution (such as ozone destruction, acid rain, (...) and nitrate leaching) and of health and welfare, which are associated with cattle production, are critically reviewed. The possibilities of integrating cattle production with other types of production are evaluated. Cattle can be used for single purposes such as dairy, beef, and draught, but dairy cows can also be used for restricted suckling combining dairy and beef production. In addition a mixture of species makes grazing more efficient, and a combination of cattle and mixed cropping can increase resource efficiency. (shrink)

Friesen's comparison between classroom practices and digital dissection carries the flaws of treating the digital and non-digital learning materials differently when comparing. This reply paper argues for a symmetric comparison through a focus on the way in which comparability between digital and non-digital learning materials is established by the researcher. It is suggested that such comparison might have brought about a result more favorable for digital technology.

The following text presents a revised and extended version of the public defence of my Ph.D. thesis, which I presented at the Faculty of Social Sciences on 18 th November 2005, Copenhagen University. The thesis applies and develops theoretical perspectives from Science and Technology Studies – especially Actor-Network Theory – on the empirical field of primary education. This field has not prior been approached by these theories. Based on ethnographic field studies the thesis presents and compares what I call spatial (...) imaginaries of interactions of humans and learning materials in a traditional classroom and in a computer lab. The study describes and discusses the forms of knowledge and the forms of presence performed through these socio-material interactions. The study thus contributes a definition of materialities that takes the understanding of technology in education beyond the dominant humanist approach to schooling. (shrink)

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)

A paradigmatic aspect of a paradigmatic kind of right is that the rights holder is the only one who can alienate it. When individuals waive rights, the normative source of that waiving is normally taken to be the individual herself. This moral feature?immunity?is usually in the background of discussions about rights. We bring it into the foreground here, with specific attention to a recent U.S. Supreme Court decision, Kentucky v. King (2011), concerning search and seizure rights. An entailment of the (...) Court's decision is that, at least in some cases, a right can be removed by the intentional actions of the very party against whom the right supposedly protects the rights holder. We argue that the Court's decision is mistaken. The police officers in the case were not morally permitted, and should not be legally permitted, to intentionally create the very circumstances that result in the removal of an individual's right against forced, warrantless search and seizure. (shrink)

Bio-art epitomizes a coalescence of art and sciences. It is an emerging contemporary artistic practice that uses a wide range of traditional artistic media interwoven with new artistic media that are biological in nature. This includes molecules, genes, cells, tissues, organs, living organisms, ecological niches, landscapes and ecosystems. In addition, bio-art expands into conceptual art using biological processes such as growth, cell division, photosynthesis and concepts of the origin of life and evolution, explaining them as new artistic media. In this (...) time of global challenges, bio-art communicates thoughts and feelings that involve relationships between the artist, science, public and the biological organism or biological concept. This article reviews the major challenges and driving forces that contributed to emerging biology-centered art and design. (shrink)

Oncogene activation leads to cellular transformation by deregulation of biological processes such as proliferation and metabolism. Paradoxically, this can also sensitize cells to nutrient deprivation, potentially representing an Achilles' heel in early stage tumors. The mechanisms underlying this phenotype include loss of energetic and redox homeostasis as a result of metabolic reprogramming, favoring synthesis of macromolecules. Moreover, an emerging mechanism involving the deregulation of mRNA translation elongation through inhibition of eukaryotic elongation factor 2 kinase (eEF2K) is presented. The potential consequences (...) of eEF2K deregulation leading to cell death under nutrient depletion are discussed. Finally, the relevance of eEF2K as a master regulator of the response to nutrient deprivation in vivo, and its potential exploitation for therapeutic targeting of cancers, are elaborated. Overall, a better understanding of the adaptive mechanisms allowing tumors to circumvent oncogene‐induced hypersensitivity to nutrient deprivation is a promising avenue for uncovering novel therapeutic targets in cancers. (shrink)

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)

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)

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)