Roy Sorensen

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

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

Stereotypically, computation involves intrinsic changes to the medium of representation: writing new symbols, erasing old symbols, turning gears, flipping switches, sliding abacus beads. Perspectival computation leaves the original inscriptions untouched. The problem solver obtains the output by merely alters his orientation toward the input. There is no rewriting or copying of the input inscriptions; the output inscriptions are numerically identical to the input inscriptions. This suggests a loophole through some of the computational limits apparently imposed by physics. There can be symbol manipulation without inscription manipulation because symbols are complex objects that have manipulatable elements besides their inscriptions. Since a written symbol is an ordered pair of consisting of a shape and the reader's orientation to that inscription, the symbol can be changed by changing the orientation rather than inscription. Although there are the usual physical limits associated with reading the answer, the computation is itself instantaneous. This is true even when the sub-calculations are algorithmically complex, exponentially increasing or even infinite

The poster boy for my paper is the King's Messenger in Lewis Carroll's Through the Looking Glass. Recall that since the White Queen lives backwards, her memory works forwards. She pities Alice who can only remember things after they happen. Alice asks which things the Queen remembers best: `Oh, things that happened the week after next,' the Queen replied in a careless tone. `For instance, . . . there's the King's Messenger. He's in prison now, being punished: and the trial doesn't even begin till next Wednesday: and of course the crime comes last of all.' (Chapter V) Is the King's Messenger being treated unjustly? Why not prepunish people for their future crimes? True, it is generally easier to have knowledge about past crimes than future crimes. But is unpredictability the only problem with prepunishment?

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.

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.

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

If you read this abstract, then you will understand what my essay is about. Under what conditions would the preceding assertion be a lie? Traditional definitions of lying are always applied to straight declaratives such as ‘The dog ate my homework’. This one sided diet of examples leaves us unprepared for sentences in which conditional probability governs assertibility. The truth-value of conditionals does not play a significant role in the sincere assertion of conditionals. Lying is insincere assertion. So the connection between lying and falsehood is broken when lying with conditionals. Drawing on Frank Jackson's account of indicative conditionals. I argue that it is possible to lie with true conditionals by virtue of their false conventional implicatures. False conversational implicatures only guarantee misleading assertions, not lies. Lying remains a semantic rather than a pragmatic affair.

Kripshe treats ‘god’ as an empty natural kind term such as ‘unicorn’. She applies Saul Kripke's fresh views about empty natural kinds to ‘god’. Metaphysically, says Kripshe, there are no possible worlds in which there are gods. Gods could not have existed, given that they do not actually exist and never did. Epistemologically, godlessness is an a posteriori discovery. Kripshe dismisses the gods in the same breath that she dismisses mermaids. Semantically, the perspective Kripshe finds most perspicacious, no counterfactual situation is properly describable as one in which there are gods. Perhaps it is not quite a necessary truth that there are no gods. According to Saul Kripke, failed natural kind terms are ill-defined. Incorporating ill-defined terms into declarative sentences yields only mock propositions. Just as the meteorologist has no professional interest in mock thunder, the logician has no professional interest in mock propositions. Kripshe disagrees with agnostics who assign a low probability to ‘There is at least one god’. The bearers of probabilities must be propositions. Despite this deference to science, Kripshe agrees with the a priori atheist that, necessarily, no future experience could constitute an encounter with a god. Divine revelation is impossible. Kripshe's a posteriori necessary atheism compares favorably to familiar forms of atheism and to non-cognitivists. It reveals interesting challenges to a coherent formulation of atheism.

Poindexter points and asserts `That is Clinton''. But it is vague as to whether he pointed at Clinton or pointed at the more salient man, Gore. Since the vagueness only occurs at the level of reference fixing, the content of the identity proposition is precise. Indeed, it is either a necessary truth or a necessary falsehood. Since Poindexter''s utterance has a hidden truth value by virtue of vagueness, it increases the plausibility of epistemicism. Epistemicism says that vague statements have hidden truth values. If a precise statement can have a hidden truth value conferred indirectly by vaguesness, then a vague statement can have a hidden truth value directly by its own vagueness.

Semantic indeterminacy is the ether of philosophy of language. It fills the interstices of our intentions and pervades accounts of presupposition, tense, fiction, translation, and especially, vagueness. Yet semantic indeterminacy is as impossible as ectoplasm. Indeed, more so! The demonstration need only borrow a few assumptions used elsewhere in widely accepted impossibility results. Since an impossibility is never a necessary condition for anything actual, semantic indeterminacy must be superfluous. Language is no more explained by semantic indeterminacy than calculus is explained by (pre-Robinsonian) infinitesimals.

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

Is listening to music like looking through a kaleidoscope? Formalists contend that music is meaningless. Most music theorists concede that this austere thesis is surprisingly close to the truth. Nevertheless, they refute formalism with a little band of diffusely referential phenomena, such as musical quotation, onomatopoeia, exemplification, and leitmotifs. These curiosities ought to be pressed into a new campaign against assumptions that vagueness can only arise in the semantically lush setting of language. Just as the discovery of extremophilic bacteria led biologists to revise their opinions about the scope and preconditions of life, the marginal forms of reference that survive in the semantic desert of absolute music should lead philosophers to revise their assumptions much about scope and preconditions of vagueness.

William of Ockham wrote, ‘It is futile to do with more things that which can be done with fewer .’ But what if each option uses less than its predecessor but no option uses the least? A scale perfectly balanced between a pair of kilogram weights can be tipped by adding half a kilogram to one side, or a quarter of a kilogram, or an eighth of a kilogram, or … For any choice, there is an option that gets the job done with less. Relative futility does not entail absolute futility. The job can get done – but only if we use superfluous means. Is this a refutation of Ockham’s Razor or just a close shave?