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.
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)
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.
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)
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)
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)
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)
Creationists believe that C. K. Chesterton created Father Brown in his detective stories. Since creating implies a creation, Father Brown exists. Atheists object that the same reasoning could prove the existence of God. But creationists such as Jonathan Schaffer insist atheists do believe that God exists. Serious metaphysics rarely concerns existence. The disagreement between the theist and the atheist is about the nature of God, not His existence. Schaffer underestimates the religious imagination. There could be a religion that explicitly regarded (...) God as a fictional character. The tenets of this, presently hypothetical, religion are developed in a dialogue. (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)
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.
This is a reply to Casey O'Callaghan and Jonathan Westphal’s comments on Seeing Dark Things: The Philosophy of Shadows. Both attempt to soften the blow to intuition that comes from the most controversial thesis of the book: we see the backs of back-lit objects. Each characterizes the viewing of silhouettes as a kind of marginal seeing that only discloses shapes, sizes and location. In response, photographs are presented to show that silhouettes are typically three-dimensional and they often have internal structure. (...) Consider the silhouette of a bird fluttering inside a cage; we see more than the outline of the cage. Orbiting this main point are subsidiary points about the distinction between shade and shadows, the nature of occlusion, the color black, and peculiarities of absent absences. (shrink)
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)
Mights plug gaps. If p lacks a truth-value, then ‘It might be that p’ should also lack truth-value. Yet epistemic hedges often turn an unassertible statement into an assertible one. The phenomenon is illustrated in detail for two kinds of statements that are frequently alleged to be counterexamples to the principle of bivalence: future contingents and statements that apply predicates to borderline cases. The paper concludes by exploring the prospects for generalizing this gap-plugging strategy.
Positive thinkers love Watty Piper's The little engine that could. The story features a train laden with toys for deserving children on the other side of the mountain. After the locomotive breaks down, a sequence of snooty locomotives come up the track. Each engine refuses to pull the train up the mountain. They are followed by a weary old locomotive that declines, saying "I cannot. I cannot. I cannot." But then a bright blue engine comes up the track. He manages (...) to chug over the mountain by averring "I think I can. I think I can. I think can.". (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 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.
The principle of charity says that all agents are rational. The principle of meta-charity says that all agents believe all agents are rational. My thesis is that the arguments which are used to support charity also support meta-charity. Meta-charity implies meta-meta-charity. By recursion, the principle of charity implies that it is common knowledge. But there appears to be intelligent, well-informed disagreement with the principle of charity. So if the entailment thesis holds, opponents of the principle of charity have a new (...) objection to the principle. Defenders of the principle of charity must either refute the entailment thesis or accept much stronger consequences than they expected. (shrink)
Vagueness theorists tend to think that evolutionary theory dissolves the riddle "Which came first, the chicken or the egg?". After all, 'chicken' is vague. The idea is that Charles Darwin demonstrated that the chicken was preceded by borderline chickens and so it is simply indeterminate as to where the pre-chickens end and the chickens begin.
A flop is a picture that mirror reverses the original scene. Some flops are reversed copies. For instance, mirror reversal is systematic with technologies that require contact between a template and an imprint surface. Other flops are just pictures that have undergone the operation of flopping. For example, a slide that is inserted backwards into a projector is a flop.
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. (shrink)
A blindspot is a consistent but inaccessible proposition. For instance, I cannot know 'The test is on Friday but I do not know it'. No contradiction follows from the supposition that you know my blindspot. But could you know my blindspot if we are epistemic peers? Epistemic peers have the same evidence and reasoning ability. So either both peers know a proposition or both are ignorant. Since I cannot know my blindspot, neither can my peer. Thus the formal ignorance associated (...) with blindspots spreads to my peers. This contagion is used to improve a solution to the blindspot solution to the surprise test paradox. (shrink)
Lake Tanganiyka has lefty and righty cichlid fish that show there can be natural selection for a trait over its mirror image counterpart.This raises the question Can there be biological selection of a whole organism over its mirror image counterpart? That is, could the fitness of a fish be altered by simply changing it into its own enantaniomorph? My answer is no. I present Flatlander thought experiment to demonstrate that mirror imagecounterparts are duplicates because they only differ in how they (...) happen to be oriented in space. The counterparts have the same intrinsic properties and are in the same environment,so there can be no difference in fitness. (shrink)
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. (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)