Mental time travel is the ability to mentally project oneself backward in time to relive past experiences and forward in time to pre-live possible future experiences. Previous work has focused on MTT in its voluntary form. Here, we introduce the notion of involuntary MTT. We examined involuntary versus voluntary and past versus future MTT in a diary study. We found that involuntary future event representations—defined as representations of possible personal future events that come to mind with no preceding search attempts—were (...) as common as involuntary autobiographical memories and similar to them regarding cuing and subjective qualities. Future MTT involved more positive and idyllic representations than past MTT. MTT into the distant future/past involved more representations of cultural life script events than MTT into the immediate past/future. The findings are discussed in relation to cultural learning and MTT considered as a higher mental process. (shrink)

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)

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?

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)

We investigated whether memories are selected for the life story based on event characteristics. Sixty-one students completed weekly diaries over their first term at university. They described, dated and rated two events each week. Three months after the end of the term they completed an unexpected memory test. They recalled three memories from the diary period that were important to their life story. Three randomly selected events scoring low on importance to the life story functioned as control memories. Life story (...) memories were rated higher on goal relevance, emotional intensity, importance and rehearsal in the diary and maintained their higher ratings at the test session, while ratings for control memories dropped off. Life story memories’ content was less consistent over time but they were more accurately dated than control memories. The results suggest that event characteristics play an important role for the selection of life story memories. (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.

Involuntary autobiographical memories are spontaneously arising memories of personal events, whereas voluntary memories are retrieved strategically. Voluntary remembering has been studied in numerous experiments while involuntary remembering has been largely ignored. It is generally assumed that voluntary recall is the standard way of remembering, whereas involuntary recall is the exception. However, little is known about the actual frequency of these two types of remembering in daily life. Here, 48 Danish undergraduates recorded their involuntary versus voluntary autobiographical memories during a day (...) using a mechanical counter. Involuntary memories were reported three times as frequently as voluntary memories. Compared to voluntary memories, they were associated less with problem solving and social sharing and more with day dreaming, periods of boredom, no reasons for remembering and predominantly came to mind during unfocused attention. The findings suggest that involuntary recall is a typical way of accessing the personal past. (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)

Mental time travel is the ability to mentally project oneself into one’s personal past or future, in terms of memories of past events or projections of possible future events. We investigated the frequency and valence of involuntary MTT in the context of high trait worry. High and low worriers recorded the frequency and valence of involuntary memories and future projections using a structured notebook and completed measures probing individual differences related to negative affectivity. Involuntary future projections were as frequent as (...) involuntary memories. We found a positivity bias for both past and future MTT, in that fewer negative events were reported than positive or neutral ones. This positivity bias was greater for future than for past events. Individual differences related to negative affectivity were positively associated with the proportion of negative events, indicating a reduced positivity bias in individuals with a general tendency to experience negative affect. (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.

There is no doubt that episodic memory serves communicative functions, but Mahr & Csibra overlook that this is not the only function served by memories of past events. Autobiographical memory research has identified several other functions, including purely directive functions. The functionality of episodic memory is not stable across situations; it varies dynamically with the demands of the retrieval context.

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)

This study compares involuntary and voluntary autobiographical memories in depressed and never depressed individuals. Twenty depressed and twenty never depressed individuals completed a memory diary; recording their reactions to 10 involuntary and 10 voluntary memories over 14–30 days. Psychiatric status , psychopathology, rumination and avoidance were assessed. For both groups, involuntary memories more frequently lead to strong reactions than voluntarily memories. For both modes of retrieval, depressed individuals reported more frequent negative reactions than never depressed individuals and rated memories as (...) more central to identity with higher levels of rumination and avoidance. Depressed individuals retrieved both positive and negative memories during involuntary retrieval. These findings support the view that involuntary memory retrieval represents a basic mode of retrieval during healthy and disordered cognition, and that during depression, both involuntary and voluntary memories are central to identity and associated with rumination and avoidance. (shrink)

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

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.

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)

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)

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.

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 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)

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 introductory chapter begins with a brief description of the purpose of this book, which is to present a general theory of thought experiments. The discussion includes thought experiments from many disparate fields, ranging from aesthetics to zoology. The primary goal is to establish true and interesting generalizations about them. Success here will radiate to the secondary goal of understanding philosophical thought experiments. An overview of the subsequent chapters is presented.

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 presents and motivates the issues surrounding thought experiments by assembling the case against their use. It begins by exploring the more specific charge that thought experiment is just introspection, then concentrates on the charge that it is merely an atavistic appeal to ordinary language. Even if thought experiment is distinct from either of these methods, it strongly resembles them. Hence, details of both introspection and the appeal to ordinary language will be discussed in the hope of illuminating thought (...) experiment at least by analogy. Finally, a more general problem about the informativeness of thought experiment is developed. (shrink)

But a winner must supply a nonevasive picture with no limit on potential detail--a purely imagistic depiction that does not rely on a mere description of an impossibility. There are logical minded philosophers from David Hume to Saul Kripke who think the prize cannot be won: What is conceivable is possible and whatever is depicted is thereby conceived, therefore, impossibilities cannot be depicted. Yet there is a rich aesthetics of inconsistency, best known through M. C. Escher. So I proceed with (...) the fine print for the competition. (shrink)

This chapter lays out a classification scheme for thought experiments. A good scheme consolidates knowledge in a way that minimizes the demand on your memory and expedites the acquisition of new knowledge by raising helpful leading questions. Thought experiments are all reducible to two highly specific forms of paradox — one targeting statements implying necessities, the other targeting statements implying possibilities. By treating a thought experiment as a stylized paradox, the idea that it reveals inconsistencies is matured. The chapter also (...) exposes the structure of our ensuing ambivalence, as well as the structure of resolutions. (shrink)