Logic Works is a critical and extensive introduction to logic. It asks questions about why systems of logic are as they are, how they relate to ordinary language and ordinary reasoning, and what alternatives there might be to classical logical doctrines. It considers how logical analysis can be applied to carefully represent the reasoning employed in academic and scientific work, better understand that reasoning, and identify its hidden premises. Aiming to be as much a reference work and handbook for further, (...) independent study as a course text, it covers more material than is typically covered in an introductory course. -/- Topics include: translation, proofs, and trees for sentential and predicate logic with identity, definite descriptions, and functional terms; normal forms; proofs and trees for the principal normal modal systems; an introduction to second order and quantified modal logic; formal syntax and semantics; mathematical induction; metatheory for many of these systems; semantics and trees for free logic, intuitionistic logic, and three-valued and paraconsistent logics. -/- A companion website contains a detailed student solutions manual with a running commentary on all starred exercises and a set of editable slides for instructors to customize their courses. (shrink)

Reid maintained that the perceptions that we obtain from the senses of smell, taste, hearing, and touch are ‘suggested’ by corresponding sensations. However, he made an exception for the sense of vision. According to Reid, our perceptions of the real figure, position, and magnitude of bodies are suggested by their visible appearances, which are not sensations but objects of perception in their own right. These visible appearances have figure, position, and magnitude, as well as ‘colour,’ and the standard view among (...) Reid scholars has been that Reid maintained that our perceptions of visible figure, position, and magnitude are also not suggested by any sensation. They are instead suggested by the material impression on the retina. Gideon Yaffe challenges the standard interpretation. According to Yaffe, Reid believed that our perceptions of visible figure are suggested by corresponding sensations, by sensations of colour. We defend the standard interpretation of Reid. According to Reid, there is no “local sign” in our sensations of colour. The same colour sensation can be associated with different positions on the visual field, and different colour sensations can be associated to the same position on the visual field. According to Reid, we only have evidence for a correlation between the image on the retina and the perception of visible figure. (shrink)

This paper was originally published in _Journal of the History of Ideas_ 51 (1990): 573-597. Kant's claim that space and time are "forms of intuition" is contrasted with the nativist claim that space is an innate idea or construct of the mind and with the empiricist claim that space is given in or learned from experience. It is argued that the nativism/empiricism debate masks a more fundamental disagreement between sensationism and constructivism. Kant's account of space- and time-cognition is shown to (...) be neither sensationist nor constructivist and as a consequence to be "nativistic" in a sense which commentators from Vaihinger and Kemp Smith to Patricia Kitcher have failed to capture. (shrink)

This is the first edition in over a century to present David Hume's Enquiry concerning Human Understanding, Dissertation on the Passions, Enquiry concerning the Principles of Morals, and Natural History of Religion in the format he intended: collected together in a single volume. Hume has suffered a fate unusual among great philosophers. His principal philosophical work is no longer published in the form in which he intended it to be read. It has been divided into separate parts, only some of (...) which continue to be published. This volume repairs that neglect by presenting the four pieces that Hume in later life desired to "alone be regarded as containing [his] philosophical sentiments and principles" in the format he preferred, as a single volume with an organization that parallels that of his early Treatise of Human Nature. This edition's introduction comments on the historical origins and evolution of the four parts and draws attention to how they mutually inform and support one another. The text is based on the first (1758) edition of Hume's Essays and Treatises on Several Subjects. Notes advise the reader of the changes made in the final (1777) edition. Excerpts from the work of some of Hume's most important contemporary critics are included as appendices. Hume's abundant references to ancient historians, geographers, poets, and philosophers—many of them now quite obscure—are rendered accessible in this volume through extensive textual notes and a bibliography of online sources. (shrink)

David Hume’s philosophical work presents the reader with a perplexing mix of constructive accounts of empirically guided belief and destructive sceptical arguments against all belief. This book reconciles this conflict by showing that Hume intended his scepticism to be remedial. It immunizes us against the influence of “unphilosophical” causes of belief, determining us to proportion our beliefs to the evidence. In making this case, this book develops Humean positions on topics Hume did not discuss in detail but that are of (...) interest to contemporary philosophers: consciousness and the unity of consciousness, temporal experience, visual spatial perception, the experience of colour and other qualia, objective experience, and spatially extended minds. It also challenges currently accepted interpretations of Hume’s views on the finite divisibility of space and time, vacuum, the duration of unchanging objects, and identity over time. It deals with criticisms of Hume that were raised by his contemporaries, notably by Thomas Reid, draws attention to earlier seventeenth‑ and eighteenth‑century work that has bearing on the interpretation of Hume’s thought, and compares Hume’s achievements with those of later nineteenth‑century psychologists and philosophers. (shrink)

This book presents a paragraph-by-paragraph analysis of all of the major arguments and explanations in the "aesthetic" of Kant's Critique of Pure Reason. The first part of the book aims to provide a clear analysis of the meanings of the terms Kant uses to name faculties and types of representation, the second offers a thorough account of the reasoning behind the "metaphysical" and "transcendental" expositions, and the third investigates the basis for Kant's major conclusions about space, time, appearances, things in (...) themselves, and the cognitive constitution of the subject. A major goal of the work is to establish that Kant takes spatiotemporal form to be originally given through the constitution of the subject's receptive faculty, not generated through synthetic procedures of the imagination or understanding. (shrink)

(This paper has since been republished in _Kant's Critique of Pure Reason: Critical Essays_, edited by Patricia Kitcher [Lanham: Rowman and Littlefield, 1998], 21-44.) Kant's claim that space and time are "forms of intuition" is contrasted with the nativist claim that space is an innate idea or construct of the mind and with the empiricist claim that space is given in or learned from experience. It is argued that the nativism/empiricism debate masks a more fundamental disagreement between sensationism and constructivism. (...) Kant's account of space- and time-cognition is shown to be neither sensationist nor constructivist and as a consequence to be "nativistic" in a sense which commentators from Vaihinger and Kemp Smith to Patricia Kitcher have failed to capture. (shrink)

(Originally published in _Reid Studies_ 4 (2000-01): 35-51.) Reid and Berkeley disagreed over whether we directly perceive objects located outside of us in a surrounding space, commonly revealed by both vision and touch. Berkeley considered a successful account of erect vision to be crucial for deciding this dispute, at one point calling it ‘the principal point in the whole optic theory.’ Reid's critique of Berkeley's position on this topic is very brief, and appears to miss Berkeley's point. I argue that (...) there is more to Reid's response to Berkeley than at first meets the eye. Reid's rival account of erect vision draws on evidence that makes a compelling case for the position that we see the same space that we touch. (shrink)

Hume had two principal arguments for denying that we can have an idea of a vacuum, an argument from the non-entity of unqualified points and an argument from the impossibility of forming abstract ideas of manners of disposition. He also made two serious concessions to the opposed view that we can indeed form ideas of vacua, namely, that bodies that have nothing sensible disposed between them may permit the interposition of other bodies without any apparent motion or occlusion and that (...) it is possible to conceive the contents of a room to be evacuated without being compelled to conceive the walls moving into contact. To reconcile these concessions with his arguments and show why we only “falsely imagine” that we can form the idea of a vacuum, Hume developed a psychological theory of the perception of “invisible and intangible distance” that has something in common with Berkeley’s account of the perception of outward distance. This paper argues that this theory is both untenable and inconsistent with fundamental Humean principles. It explains why Hume should have rejected the two arguments against the idea of a vacuum and why accepting ideas of vacua would have been more in line with the rest of his thought than attempting to deny that we have any such ideas. (shrink)

Scholars have almost universally agreed that Hume's account of space and time as manners of disposition of impressions is inconsistent with one of the most fundamental tenets of his empiricism: the thesis that all ideas are derived from simple impressions. This paper challenges that view and argues that Hume's position on the origin of our ideas of space and time is a profound, original, virtually unique, and even courageous approach to the problem of original space and time cognition, and a (...) theory that allows for hitherto unrecognized expansions to the resources available to his empiricism. (shrink)

Hume appears to have sometimes taken religion to be founded on reason, at other times to have taken it to be founded on faith, and at yet other times to be based on authority. All of these views can be found in the different pieces collected together in the second volume of his Essays and Treatises on Several Subjects. By means of an analysis of what Hume meant by "genuine religion," "true religion," and "rational religion," I uncover a consistent, sincere (...) view that Hume sustained throughout his published works. This view is atheistic. (shrink)

Kant defined ‘sensation’as ‘the effect of an object on the representative capacity, so far as we are affected by it.’ This is, to put it mildly, not one among his more elegant, clear or helpful sayings. And it is merely an instance of a more general malaise. Kant did not say as much about sensation as he should have, and his account-or lack of it-can be seen at the root of many of the difficulties that have plagued his readers.

This paper contrasts three different positions taken by 18th century British scholars on how sensations, particularly sensations of colour and touch, come to be localized in space: Berkeley’s view that we learn to localize ideas of colour by associating certain purely qualitative features of those ideas with ideas of touch and motion, Hume’s view that visual and tangible impressions are originally disposed in space, and Reid’s view that we are innately disposed to refer appearances of colour to the end of (...) a line passing through the centre of the eye and originating from the spot on the back of the retina where the material impression causing that appearance was received. Reid’s reasons for rejecting the Berkeleian and Humean views are examined. It is argued that Reid’s position on visual localization is ultimately driven by his dualistic metaphysical commitments rather than by an empirically grounded investigation of the phenomena of vision. To this extent, his position sits uncomfortably with his own methodological commitments. (shrink)

This paper outlines the history of the distinction between a higher and a lower cognitive function up to Kant. It is argued that Kant initially drew the distinction in Scholastic terms--as a distinction between a capacity to image particulars and a capacity to represent universals. However, features of his project in the Critique led him to reformulate the distinction in terms of immediacy and mediacy. Nonetheless, for certain purposes the older, Scholastic distinction retained its attractiveness, and this is the ground (...) for much of the subsequent difficulty with his account of intuitions and concepts. (shrink)

Reid is well known for rejecting the "philosophy of ideas"--a theory of mental representation that he claimed to find in its most vitriolic form in Hume. But there was another component of Hume's philosophy that exerted an equally powerful influence on Reid: Hume's attack on the notion of spiritual substance in _Treatise 1.4.5. I summarize this neglected aspect of Hume's philosophy and argue that much of Reid's epistemology can be explained as an attempt to buttress dualism against the effects of (...) Hume's critique. (shrink)

This paper considers an objection to the Humean view that perception involves introspective acquaintance with representative images. The objection, originally raised by Thomas Reid and recently endorsed by Nicholas Wolterstorff, states that no representative image can be hard, and concludes that acquaintance with such images cannot therefore account for our perception of hardness. I argue in response that a case has not been made for denying that representative images can be hard. Hardness, as understood by Hume and Reid, is the (...) quality of having parts that resist motion relative to one another. This means that as long as it is allowed that representative images can consist of spatially disposed parts, there can be no a priori reason to deny that they might be hard as well. (shrink)

This paper examines Berkeley's attitude toward our perception of spatial relations on the two- dimensional visual field. This is a topic on which there has been some controversy. Historians of visual theory have tended to suppose that Berkeley took "all" spatial relations to be derived in the way our knowledge of depth is: from association of more primitive sensations which are themselves in no way spatial. But many philosophers commenting on Berkeley have supposed that he takes our awareness of two- (...) dimensional visual layout to be directly perceived. I argue that Berkeley's position on this issue is deeply ambivalent and that neither alternative sits well with the rest of his philosophy. (shrink)

On the basis of an examination of Kant's correspondence with Mendelssohn, 1766-1770, I argue that already in 1770 Kant had before him a decisive refutation of the view that time is imposed by the mind on its representations, and that Kant did not hold any such view of the subjectivity of time in his later work. Kant's mature view is that time is subjective only in the sense that it is the manner in which the empirically observable subject receives sensory (...) matter, not in the sense that the subject actually produces this manner of receptivity. (shrink)

In “Hume on Geometry and Infinite Divisibility in the Treatise”, H. Mark Pressman charges that “the geometry Hume presents in the Treatise faces a serious set of problems”. This may well be; however, at least one of the charges Pressman levels against Hume invokes a false dichotomy, and a second rests on a non sequitur.

I argue that Kant's refutation of Mendelssohn's proof of the immortality of the soul also refutes his own proof of the permanence of material substance. To evade this result, Kant would have had to rely on premises that can only be established empirically. This difficulty brings up deep and disturbing difficulties with Kant's theory of matter and body in his Metaphysical Foundations of Natural Science and suggests that his early Physical Monadology offered a better account, one he was constrained by (...) later commitments to abandon to the detriment of the coherence of his matter theory. (shrink)

This is a wide ranging survey of the extent and nature of Reid's nativist commitments and of their implications for his account of perception and his realism.

Anthony Quinton has argued that the trouble with Kant is that he does not take empirical experience to have any significant role to play in our knowledge of the world, and as a result is forced to take the imposition of a priori forms and categories to be arbitrary and unguided. While Quinton has pointed to a serious short-coming with those more rationalistic interpretations of Kant that would ascribe a dominant role to the understanding or the imagination in constituting experience, (...) I make a case for an empiricist reading of Kant that, by taking significant aspects of our empirical intuitions to be simply given prior to any intellectual or imaginative acts, is able to circumvent the difficulties Quinton has raised. (shrink)

This chapter on classical empiricism is divided into three sections, namely, absolutism, idealism, and memory. Presentism poses a particular problem for the empiricist view that the idea of time arises from people's experience of the succession of their ideas. The view that time passes independently of the succession of ideas was shared by canonically empiricist philosophers, such as Gassendi, Locke, and Newton. The idea of time arises from a compound impression that consists of successively disposed simple impressions – impressions that (...) may be identical in all respects but for their manner of disposition, and that may be disposed on either side of an unoccupied gap. People's experience is not confined to the present moment. The truly radical implication is that the past is not destroyed. It persists, not into the present by way of a trace or echo, but in the past, which continues to be visible to consciousness. (shrink)

This paper offers and account of the "system" of probable reasoning presented in Hume's Treatise and first Enquiry. The system is sceptical because it takes our beliefs to be the product of naturally occurring psychological mechanisms rather than logically sound judgment, and because it declares those beliefs to be ultimately unjustifiable. This paper explains how Hume was nonetheless able to provide for a logic of probable reasoning, grounded on natural, but unjustifiable beliefs.

In Book 1, Part 2, Section 3 of his _Treatise of Human Nature_, David Hume argued that the idea of time arises from the experience of succession. In doing so, he raised a difficult question about the nature of that experience. The experience must be an experience had over time, not an experience of time. But how is that possible? This paper investigates how far mechanisms Hume appealed to when accounting for such related phenomena as causal inference, the understanding of (...) abstract terms and the attribution of necessitating power to causes – habituation, the formation of expectations and the projection of feelings – can serve as a Humean way of defending Hume's account of temporal experience. In passing the paper questions the soundness of Hume's arguments for concluding that it is impossible to experience time without experiencing change. (shrink)

An overview of Kant's arguments in the "Transcendental Aesthetic" with remarks on some of the most significant recent literature on the topic.

Against the claims of Russell, Goodman, and Albert Casullo, this paper argues that the location of phenomena in visual space cannot be determined through reference to monadic local properties of the visual field.

Drawing on work done by Helmholtz, I argue that Reid was in no position to infer that objects appear as if projected on the inner surface of a sphere, or that they have the geometric properties of such projections even though they do not look concave towards the eye. A careful consideration of the phenomena of visual experience, as further illuminated by the practice of visual artists, should have led him to conclude that the sides of visible appearances either look (...) straight, in which case their angles appear to approximate Euclidean measures, or their angles do not appear to approximate Euclidean measures for straight line figures, in which case their sides do not look straight. (shrink)

In this paper I argue that Hume's thought on comportment between the sexes developed over time. In the Treatise he was interested in explaining why the world seeks to impose artificial virtues of chastity and modesty on women and girls, and how it manages to do this so successfully. But as time passed he became increasingly concerned with justice towards women and the role of free interactions between the sexes in facilitating sociability. While his later work continues to explain the (...) origin of the artificial female virtues of chastity and modesty in the way he had in the Treatise, it also recognizes and condemns proprietary attitudes towards women and surveys various ways of achieving a balance between male jealousy and sociability. It concludes by condemning the male vices of jealousy and "gallantry" while suggesting that the emphasis on female chastity and modesty is excessive. (shrink)

A survey of work on the philosophy of perception, mind, and mental representation by Berkeley and his early modern predecessors, notably Descartes, Hobbes, Malebranche, and Locke.

: I argue that Condillac was committed to four mutually inconsistent propositions: that the mind is unextended, that sensations are modifications of the mind, that colours are sensations, and that colours are extended. I argue that this inconsistency was not just the blunder of a second-rate philosopher, but the consequence of a deep-seated tension in the views of early modern philosophers on the nature of the mind, sensation, and secondary qualities and that more widely studied figures, notably Condillac's contemporaries, Hume (...) and Reid, were not ultimately any more successful at developing an account of vision that unproblematically avoids the paradox. In passing, I take issue with Nicholas Pastore's account of how Condillac's Treatise on Sensations deals with the visual perception of form (in A Selective History of Theories of Visual Perception). (shrink)

This paper argues that Hume was first and foremost a moral psychologist and a determinist, not a moralist. When confronting the fact of moral disagreement, notably in "A Dialogue" affixed to his moral enquiry, he maintained that it is not psychologically possible to approve of the conflicting norms of other cultures, except in the case of sometimes approving of individuals in other cultures for abiding by those objectionable norms rather than fomenting cultural upheaval. All cultures should nonetheless agree on the (...) most general and fundamental moral principles as well as on most specifics. But there are non-trivial specific cases on which there will be irreconcilable disagreements, based on conflicting beliefs concerning utilities, finer matters of taste, and uncertainties over how best to maximize conflicts between the useful/agreeable and the personal/social. In these cases, we would be wise to consider whether tolerating the conflicting views of others would be more useful and agreeable than attempting to enforce conformity. Toleration is among the less obvious virtues, but it is one that experience has by now taught us to adopt, at least in certain cases. (shrink)

The literature on Berkeley is almost unanimous in taking this claim to know the existence of other finite spirits to rest on an argument from analogy. I show that this is not so and that Berkeley uses a causal argument to prove that there are other minds. Questions of the degree to which it is legitimate for Berkeley to appeal to causes, particularly occasional causes, are addressed in the process.

We argue that Hume was wrong to identify constant conjunction in time as the sole associative principle responsible for belief. On principles that can be grounded on his own account, constant contiguity in space ought to produce the same effect. We close by examining some of the ways in which a recognition of the influence of contiguity relations might have assisted Hume in resolving problems that otherwise arise with his accounts of causality and objectivity.

(This article was republished in lightly re-edited form in _Journal of Scottish Philosophy_ 16 (2018) 175-91.) Reid and Berkeley disagreed over whether we directly perceive objects located outside of us in a surrounding space, commonly revealed by both vision and touch. Berkeley considered a successful account of erect vision to be crucial for deciding this dispute, at one point calling it ‘the principal point in the whole optic theory.’ Reid's critique of Berkeley's position on this topic is very brief, and (...) appears to miss Berkeley's point. I argue that there is more to Reid's response to Berkeley than at first meets the eye. Reid's rival account of erect vision draws on evidence that makes a compelling case for the position that we see the same space that we touch. (shrink)

There are good reasons to think that at least a part of Hume's project in the ‘The natural history of religion’ was to buttress a philosophical critique of the reasonableness of religious belief undertaken in other works, and to attack a fundamentalist account of the history of religion and the foundations of morality. But there are also problems with supposing that Hume intended to achieve either of these goals. I argue that two problems in particular – accounting for Hume's neglect (...) of revelation, and accounting for his remarks on the ‘invincibility’ of the reasons for ‘genuine theism’ – can only be resolved by recognizing that Hume's purposes in ‘The natural history’ were not fundamentally critical. If I am right, Hume's purpose was mainly to explain why ‘false’ or ‘adulterate’ forms of religious belief are so widespread and so influential. (shrink)

A survey of work on perception, mind, and mental representation by 18th century philosophers after Berkeley, notably Robert Smith, William Porterfield, David Hume, Etienne de Condillac, and Thomas Reid.

It might seem inappropriate to describe Kant as an empiricist. He believed, contrary to the basic empiricist principle, that there are nontrivial propositions that can be known independently of experience. He devoted virtually all of his efforts as a researcher to discovering how it is possible for us to have this "synthetic a priori" knowledge. However, Kant also believed that there are some things that we can know only through sensory experience. Though he did not give these empirical propositions the (...) attention he lavished on their a priori companions, they are both numerous and significant. The purpose of this article is to examine the role of empirical elements in Kant's thought, and to expand on some of the implications that a due appreciation of this empiricism has for the interpretation of his positions on causality, the systematic unity of laws, and realism. In the process a pair of hitherto neglected Kantian notions will come up for close scrutiny: those of affinity and of the exponent of a rule. (shrink)

Over _Principles_ 42-43, Berkeley worried that we might "in truth" see things existing at a distance from us, in which case they could not plausibly be supposed to exist independently of being perceived. He went on to say that he had developed his new theory of vision to address this worry. This paper argues that the worry is serious and that Berkeley was right to think that it would take nothing less than a theory of vision to address it. The (...) paper further argues that Berkeley's theory of vision fails to adequately address the worry. The locus of the failure is Berkeley's account of what he called "situation." The term has an ambiguity that Berkeley exploited. It can refer to how coloured points are localized on a two dimensional visual field or it can mean how the visual field is oriented with respect to the direction of gravity. Berkeley focused on the second when he needed to explain how the first is possible without granting that we originally experience objects as disposed over at least two spatial dimensions. (shrink)

This book symposium contribution focuses on James Van Cleve's assertion that Reid's dualistic commitments are not essential to his other doctrines. I argue to the contrary that his critique of what he called the philosophy of ideas depends on a tacit assumption of dualism.

Book 1, Part 4, Section 5 of Hume’s Treatise is taken up with a response to an argument for the immateriality of the soul that Hume considered “remarkable,” and that Kant was later to describes as the “Achilles” (the strongest) of all the arguments for this conclusion. This paper surveys versions of the argument offered by Cudworth, Bayle, and Clarke before going on to argue that Hume’s own treatment of the argument departs from the standard in a number of important (...) ways. The departures restate the argument in Humean terms, replacing premises concerning inherence, substance, and action, which Hume considered to be false or unintelligible, with ones mentioning conjunction at a location in space, which he considered to be at least intelligible. These changes challenge the view that Treatise 1.4.5 was intended as a satire or a lampoon. A satire or lampoon exposes a flat statement of its target view to ridicule. It does not modify that view— certainly not by way of introducing improvements to make it more intelligible. Hume meant to endorse what he said in Treatise 1.4.5. In particular, he meant to endorse the tenets that that there are mental states that are spatially extended, and that it is as difficult to explain how an immaterial soul could contain extended mental images as to explain how a material soul could contain unextended thoughts. (shrink)

This paper argues that Kant's first argument in the metaphysical expositions defends a foundational insight on which much of the rest of his thought depends: that our experience of the spatial properties and relations of things is not based on comparison of the things (matters) found in space or on any form of reasoning (causal or demonstrative). Spatial and temporal relations are originally given in sensory intuition, not constructed or inferred.

Reid declared Hume's appeal to variation in the magnitude of a table with distance to be the best argument that had ever been offered for the ‘ideal hypothesis’ that we experience nothing but our own mental states. Reid's principal objection to this argument fails to apply to minimally visible points. He did establish that we have reason to take our perceptions to be caused by external objects. But his case that we directly perceive external objects is undermined by what Hume (...) had to say about the role played by color in our perception of the primary qualities of bodies. (shrink)

Recently it has been argued that there are conceivable situations in which we would be led to think of our experiences as belonging to two different, entirely disconnected spaces or times. From this it follows that there is no necessity in the claim that all our experiences must be conceived of as belonging together in one space or time. Let us call the claim that all our experiences must belong to one space and time the connectedness hypothesis, and the counterclaim (...) that there are conceivable situations in which we would be led to think of our experiences as belonging to disconnected spaces or times the discreteness hypothesis. Note that neither of these hypotheses is concerned with the nature of physical space or time: the connectedness hypothesis does not affirm that the universe can be composed only of worlds connected by some path through space or time; it affirms merely that whatever the state of the topology of the universe, we can conceive of our experiences only as related within a single space and time; the discreteness hypothesis does not affirm that the universe may be composed of two or more worlds not connected by some path through space or time; it affirms merely that it is possible for us to find ourselves in a situation where our experiences can be divided into two or more disjoint sets, such that the members of one set cannot be placed in any sort of spatiotemporal relation to the members of any other set. Perhaps either hypothesis could be used as a premise toward a conclusion about the nature of the physical world—but that would be another argument. (shrink)

Recently it has been argued that there are conceivable situations in which we would be led to think of our experiences as belonging to two different, entirely disconnected spaces or times. From this it follows that there is no necessity in the claim that all our experiences must be conceived of as belonging together in one space or time. Let us call the claim that all our experiences must belong to one space and time the connectedness hypothesis, and the counterclaim (...) that there are conceivable situations in which we would be led to think of our experiences as belonging to disconnected spaces or times the discreteness hypothesis. Note that neither of these hypotheses is concerned with the nature of physical space or time: the connectedness hypothesis does not affirm that the universe can be composed only of worlds connected by some path through space or time; it affirms merely that whatever the state of the topology of the universe, we can conceive of our experiences only as related within a single space and time; the discreteness hypothesis does not affirm that the universe may be composed of two or more worlds not connected by some path through space or time; it affirms merely that it is possible for us to find ourselves in a situation where our experiences can be divided into two or more disjoint sets, such that the members of one set cannot be placed in any sort of spatiotemporal relation to the members of any other set. Perhaps either hypothesis could be used as a premise toward a conclusion about the nature of the physical world—but that would be another argument. (shrink)