Discusses recent work on representationalism, including: the case for a representationalist theory of consciousness, which explains consciousness in terms of content; rivals such as neurobiological type-type identity theory (Papineau, McLaughlin) and naive realism (Allen, Campbell, Brewer); John Campbell and David Papineau's recent objections to representationalism; the problem of the "laws of appearance"; externalist vs internalist versions of representationalism; the relation between representationalism and the mind-body problem.

The Oxford Handbook of the Philosophy of Consciousness provides the most comprehensive overview of current philosophical research on consciousness. Featuring contributions from some of the most prominent experts in the field, it explores the wide range of types of consciousness there may be, the many psychological phenomena with which consciousness interacts, and the various views concerning the ultimate relationship between consciousness and physical reality. It is an essential and authoritative resource for anyone working in philosophy of mind or interested in (...) states of consciousness. (shrink)

Brain activity determines which relations between objects in the environment are perceived as differences and similarities in colour, smell, sound, etc. According to selectionism, brain activity does not create those relations; it only selects which of them are perceptually available to the subject on a given occasion. In effect, selectionism entails that perceptual experience is diaphanous, i.e. that sameness and difference in the phenomenal character of experience is exhausted by sameness and difference in the perceived items. It has been argued (...) that diaphaneity is undermined by phenomenological considerations and empirical evidence. This paper considers five prominent arguments of this sort and shows that none of them succeeds. (shrink)

According to constitution views of persons, we are constituted by spatially coinciding human animals. Constitution views face an ‘overpopulation’ puzzle: if the animal has my brain, there is another thinker where I am. An influential solution to this problem distinguishes between derivative and non‐derivative property possession: persons non‐derivatively have their personal properties, while inheriting others from their constituters. I will show that this solution raises a new problem, by constructing a puzzle with the absurd result that we instantiate certain properties (...) incompatibly. In setting up the puzzle, I demonstrate the relevance of the bodily awareness and self‐awareness literatures to overpopulation puzzles. (shrink)

Recent work in philosophy and cognitive science shows that knowledge is the norm of our social practice of assertion, in the sense that an assertion should express knowledge. But why should an assertion express knowledge? I hypothesize that an assertion should express knowledge because the point of assertion is to transmit knowledge. I present evidence supporting this hypothesis.

A strong form of representationalism says that every conscious property of every mental state can be identified with some part of the state’s representational properties. A weaker representationalism says that some conscious property of some mental state can be identified with some part of the state’s representational properties. David Papineau has recently argued that all such theories are incorrect since they construe consciousness as consisting in “relations to propositions or other abstract objects outside space and time”, whereas consciousness is “concrete” (...) and “here and now”. Papineau defends instead a kind of “qualia theory” according to which all conscious properties are intrinsic non-relational properties of subjects. He argues that this theory bypasses the difficulties he identifies for representationalism. Similar worries about representationalism, and similar ideas to the effect that some qualia theory, adverbial theory, or sense-datum theory fares better with respect to these worries are relatively wide-spread. I argue that Papineau’s theory does not bypass the difficulties he identifies for representationalism. In fact, Papineau’s theory arguably has no advantage at all over representationalism with regard to these issues. The features that concern Papineau about representationalist views do not derive—or do not derive solely—from the representationalism of these views. They derive from a common-factorism of these views. And this common-factorism is embraced by Papineau as well as by most theories of consciousness and perception. (shrink)

A strong form of representationalism says that every conscious property of every mental state can be identified with some part of the state’s representational properties. A weaker representationalism says that some conscious property of some mental state can be identified with some part of the state’s representational properties. David Papineau has recently argued that all such theories are incorrect since they construe consciousness as consisting in “relations to propositions or other abstract objects outside space and time”, whereas consciousness is “concrete” (...) and “here and now”. Papineau defends instead a kind of “qualia theory” according to which all conscious properties are intrinsic non-relational properties of subjects. He argues that this theory bypasses the difficulties he identifies for representationalism. Similar worries about representationalism, and similar ideas to the effect that some qualia theory, adverbial theory, or sense-datum theory fares better with respect to these worries are relatively wide-spread. I argue that Papineau’s theory does not bypass the difficulties he identifies for representationalism. In fact, Papineau’s theory arguably has no advantage at all over representationalism with regard to these issues. The features that concern Papineau about representationalist views do not derive—or do not derive solely—from the representationalism of these views. They derive from a common-factorism of these views. And this common-factorism is embraced by Papineau as well as by most theories of consciousness and perception. (shrink)

According to (what I will call) an inner awareness theory of consciousness, you are in a (phenomenally) conscious state only if you are aware, in some sense, of your being in the state. This theory is widely held, but what arguments are there for holding it? In this paper, I gather together in a systematic way the main arguments for holding the theory and suggest that none of them is persuasive. I end the paper by asking what our attitude to (...) the theory should be if there is no existing argument for it. (shrink)

The paper presents a new philosophical theory of blurred vision according to which visual experiences have two types of content: exteroceptive content, characterizing external entities, and interoceptive content, characterizing the state of the visual system. In particular, it is claimed that blurriness-related phenomenology interoceptively presents acuity of vision in relation to eye focus. The proposed theory is consistent with the representationalist thesis that phenomenal character supervenes on representational content and with the strong transparency thesis formulated in terms of mind-independentness. Furthermore, (...) the interoceptive approach is free from controversial assumptions adopted by other philosophical theories of blurred experiences and is able to account for the epistemic and motivational role of visual blur, i.e. that blurred experiences provide a prima facie justification for beliefs regarding our vision and motivate actions directed toward our eyes. (shrink)

Can perceptual experiences be states of uncertainty? We might expect them to be, if the perceptual processes from which they're generated, as well as the behaviors they help produce, take account of probabilistic information. Yet it has long been presumed that perceptual experiences purport to tell us about our environment, without hedging or qualifying. Against this long-standing view, I argue that perceptual experiences may well occasionally be states of uncertainty, but that they are never probabilistically structured. I criticize a powerful (...) line of reasoning that we should expect perceptual experience to be probabilistic, given their interfaces with unconscious probabilistic information, with behavior responsive to it, and with credences. (shrink)

I argue that perceptual consciousness is constituted by a mental activity. The mental activity in question is the activity of employing perceptual capacities, such as discriminatory, selective capacities. This is a radical view, but I hope to make it plausible. In arguing for this mental activist view, I reject orthodox views on which perceptual consciousness is analyzed in terms of peculiar entities, such as, phenomenal properties, external mind-independent properties, propositions, sense-data, qualia, or intentional objects.

The well-known phenomenological argument draws metaphysical conclusions about time, specifically about change through time and the resulting passage or flow of time, from our temporal experience. The argument begins with the phenomenological premise that there is a class of properties which underlies our experience of time and change through time, and its conclusion is that these properties are not merely experienced but exemplified. I argue that the phenomenological argument is best served by the adoption of a representational theory of perception. (...) I then present a representational theory of temporal experience. (shrink)

This paper argues for the following disjunction: either we do not live in a world with a branching temporal structure, or backwards time travel is nomologically impossible, given the initial state of the universe, or backwards time travel to our space-time location is impossible given large-scale facts about space and time. A fortiori, if backwards time travel to our location is possible, we do not live in a branching universe.

When you have a perceptual experience of a given physical object that object seems to be immediately present to you in a way it never does when you consciously think about or imagine it. Many philosophers have claimed that naïve realism (the view that to perceive is to stand in a primitive relation of acquaintance to the world) can provide a satisfying account of this phenomenological directness of perceptual experience while the content view (the view that to perceive is to (...) represent the world to be a certain way) cannot. I argue that this claim is false. Specifically, I maintain that the only acceptable naïve realist account of the relevant phenomenology is circular and that the content view can provide a similar account. In addition, I maintain that a certain specific variety of the content view provides a non-circular and thus more satisfactory account of this phenomenology. If so, then contrary to what is commonly assumed there are powerful phenomenological grounds for preferring the content view to naïve realism. (shrink)

Representationalism is, roughly, the view that experiencing is to be analyzed wholly in terms of representing. But what sorts of properties are represented in experience? According to a prominent form of representationalism, objective representationalism, experiences represent only objective (i.e. suitably mind-independent) properties. I explore subjective representationalism, the view that experiences represent at least some subjective (i.e. suitably mind-dependent) properties. Subjective representationalists, but not objective representationalists, can accommodate cases of illusion-free phenomenal inversion. Moreover, subjective representationalism captures the so-called transparency of experience, (...) as it is standardly articulated, just as well as objective representationalism. (shrink)

This paper is a contribution to the philosophical debate on visual blur from a relationalist perspective. At the same time, it offers a methodological reflection on the adequacy of explanations of phenomenal similarities and differences among perceptual experiences. The debate on seeing blurrily has been shaped by two implicit assumptions concerning our explanations of differences and similarities between experiences of seeing blurrily and other experiences. I call those assumptions into question, and argue that we do not need to provide a (...) unified explanation of the character of blurry experiences for our account to be adequate. The diversity of blurry experiences supports a different, pluralist approach to explanations of how things appear to subjects. (shrink)

Over the past few decades, as philosophers of mind have begun to rethink the sharp divide that was traditionally drawn between the phenomenal character of an experience (what it’s like to have that experience) and its intentional content (what it represents), representationalist theories of consciousness have become increasingly popular. On this view, phenomenal character is reduced to intentional content. This article explores a key motivation for this theory, namely, considerations of experiential transparency. Experience is said to be transparent in that (...) we ‘look right through it’ to the objects of that experience, and this is supposed to support the representationalist claim that there are no intrinsic aspects of our experience. (shrink)

Richard Wollheim famously argued that figurative pictures depict their scenes, in part, in virtue of their ability to elicit a unique type of visual experience in their viewers, which he called seeing-in. According to Wollheim, experiences of seeing-in are necessarily twofold, that is, they involve two aspects of visual awareness: when a viewer sees a scene in a picture, she is simultaneously aware of certain visible features of the picture surface, the picture’s design, and the scene depicted by the picture. (...) Even though Wollheim’s notion of twofoldness has been very influential, a number of philosophers have put forward powerful arguments against it. In this paper, I defend the claim that some pictorial experiences are twofold in Wollheim’s sense. My argument has two parts. In the first part, I provide a phenomenal contrast argument in favor of twofoldness. In the second part, I respond to what I take to be the most important objections against twofoldness. I believe that both parts together provide strong support for the claim that some pictorial experiences are twofold in Wollheim’s sense. (shrink)

Richard Wollheim famously argued that figurative pictures depict their scenes, in part, in virtue of their ability to elicit a unique type of visual experience in their viewers, which he called seeing-in. According to Wollheim, experiences of seeing-in are necessarily twofold, that is, they involve two aspects of visual awareness: when a viewer sees a scene in a picture, she is simultaneously aware of certain visible features of the picture surface, the picture’s design, and the scene depicted by the picture. (...) Even though Wollheim’s notion of twofoldness has been very influential, a number of philosophers have put forward powerful arguments against it. In this paper, I defend the claim that some pictorial experiences are twofold in Wollheim’s sense. My argument has two parts. In the first part, I provide a phenomenal contrast argument in favor of twofoldness. In the second part, I respond to what I take to be the most important objections against twofoldness. I believe that both parts together provide strong support for the claim that some pictorial experiences are twofold in Wollheim’s sense. (shrink)

I propose that the fundamental challenge Berkeley left realists is to account for experiences’ ability to present items as mind-independent, consistent with the claim that experiences always present themselves among the items of awareness. By exploring two ways of responding to this challenge, and ruling out the second, I hope to show that realists aiming to secure a role for experiences in grounding our grasp of mind-independence need to adopt a specific view of perceptual experience. They must take experiences to (...) have translucent aspects, and accord such aspects an essential role in presenting us with a mind-independent world. (shrink)

The idea that perceptual experience is transparent is generally used by naïve realists and externalist representationalists to promote an externalist account of the metaphysics of perceptual experience. It is claimed that the phenomenal character of our perceptual experience can be explained solely with reference to the externally located objects and properties which (for the representationalist) we represent, or which (for the naïve realist) partly constitute our experience. Internalist qualia theorists deny this, and claim that the phenomenal character of our perceptual (...) experience is internally constituted. However, my concern in this paper is not with the metaphysical debate, but with transparency as a phenomenological feature of perceptual experience. Qualia theorists have presented a number of examples of perceptual experiences which, they claim, do not even seem to be transparent; these experiences involve objects or properties which seem to be internally realized. I argue, contrary to the qualia theorist’s claim, that the phenomenal character of perceptual experience can in fact be characterized solely with reference to externally located objects and properties, and the sense in which some features of our perceptual experiences do not seem external is due to cognitive, not perceptual, phenomenology. (shrink)

Two popular theses central to recent theorizing about consciousness are the transitivity principle and the transparency of experience. According to the former, conscious mental states are mental states we are aware of in some way. According to the latter, there is some awareness-relation that we seemingly cannot bear to our experiences. I argue that, within certain reasonable constraints, there is no precisification of these theses that renders them compatible.

Those who endorse the twin theses of transparency and representationalism with regard to visual experience hold that the qualities we are aware of in such experience are, all of them, apparently possessed by external objects. They hold, therefore, that we are not introspectively aware of any qualities of visual experience itself. In this paper I argue that attention to visual noise—also known as ‘eigenlicht’ or ‘eigengrau’—puts pressure on both of these theses, though in different ways. Phenomenally, visual noise does not (...) even seem to belong to any external objects, which is a challenge to transparency. Moreover, visual noise is not the normal visual response to any distinctive external property, such as external graininess. Nor is it treated by our visual system as the perception of any such property. Given extant views of visual representation, it is therefore implausible to claim that it is the transparent representation of any such property. (shrink)

Some have argued that we can put pressure on a relational view of experience with reference to the fact that the idiosyncrasies of perceivers can affect the qualitative characters of their experiences. Quassim Cassam calls this the problem of idiosyncratic perception. I defend the relational view in response to this problem.

It has been claimed that naïve realism predicts phenomenological similarities where there are none and, thereby, mischaracterises the phenomenal character of perceptual experience. If true, this undercuts a key motivation for the view. Here, we defend naïve realism against this charge, proposing that such arguments fail (three times over). In so doing, we highlight a more general problem with critiques of naïve realism that target the purported phenomenological predictions of the view. The problem is: naïve realism, broadly construed, doesn’t make (...) phenomenological predictions of the required sort. So, as a result, opponents must resign themselves to attacking specific incarnations of naïve realism, or approach matters quite differently. (shrink)

This paper discusses a counterexample to the thesis that visual experience is cognitively impenetrable. My central claim is that sometimes visual experience is influenced by the perceiver’s beliefs, rendering her experience’s representational content indeterminate. After discussing other examples of cognitive penetrability, I focus on a certain kind of visual experience— that is, an experience that occurs under radically nonstandard conditions—and show that it may have indeterminate content, particularly with respect to low-level properties such as colors and shapes. I then explain (...) how this indeterminacy depends on the perceiver’s beliefs or thoughts. Finally, I attempt to generalize the case and show how other sorts of visual experiences can also be penetrated by beliefs and, hence, be indeterminate. (shrink)

This is a reply to commentaries on my book, The Character of Consciousness, by Benj Hellie, Christopher Peacocke, and Susanna Siegel. The reply to Hellie focuses on issues about acquaintance and transparency. The reply to Peacocke focuses on externalism about spatial experience. The reply to Siegel focuses on whether there can be Frege cases in perceptual experience.

The central thesis (CT) that this paper upholds is that a picture depicts an object by generating in those who view the picture a visual experience of that object. I begin by presenting a brief sketch of intentionalism, the theory of perception in terms of which I propose to account for pictorial experience. I then discuss Richard Wollheim’s twofoldness thesis and explain why it should be rejected. Next, I show that the socalled unique phenomenology of pictorial experience is simply an (...) instance of perceptual indeterminacy. Lastly, I discuss a phenomenon associated with pictures that could be considered a problem for CT, and account for it by invoking the thesis that visual experience is cognitively penetrable. (shrink)

We perceive a world of mind-independent macroscopic material objects such as stones, tables, trees, and animals. Our experience is the joint upshot of the way these things are and our route through them, along with the various relevant circumstances of perception; and it depends on the normal operation of our perceptual systems. How should we characterise our perceptual experience so as to respect its basis and explain its role in grounding empirical thought and knowledge? I offered an answer to this (...) question in Perception and its objects. Here I aim to clarify some of my central arguments and to develop and defend the position further in the light of subsequent critical discussion. (shrink)

This paper replies to objections from perceptual distortion against the representationalist thesis that the phenomenal characters of experiences supervene on their intentional contents. It has been argued that some pairs of distorted and undistorted experiences share contents without sharing phenomenal characters, which is incompatible with the supervenience thesis. In reply, I suggest that such cases are not counterexamples to the representationalist thesis because the contents of distorted experiences are always impoverished in some way compared to those of normal experiences. This (...) can be shown by considering limit cases of perceptual distortion, for example, maximally blurry experiences, which manifestly lack details present in clear experiences. I argue that since there is no reasonable way to draw the line between distorted experiences that have degraded content and distorted experiences that do not, we should allow that an increase in distortion is always accompanied by a change in content. This applies to perceptual distortions due to blur, double vision, perspective, and illumination conditions. (shrink)

The so-called transparency of experience (TE) is the intuition that, in introspecting one’s own experience, one is only aware of certain properties (like colors, shapes, etc.) as features of (apparently) mind-independent objects. TE is quite popular among philosophers of mind and has traditionally been used to motivate Representationalism, i.e., the view that phenomenal character is in some strong way dependent on intentionality. However, more recently, others have appealed to TE to go the opposite way and support the phenomenal intentionality view (...) (PIV), according to which intentionality is in some strong way dependent on phenomenal character. If this line of argument succeeds, then not only TE does not speak in favor of Representationalism, but it actually speaks against it, contrary to the philosophical common-sense of the last two decades. Moreover, the representationalist project of naturalizing phenomenal character turns out to be seriously undermined on the same intuitive grounds that were supposed to make it plausible. In this paper, I reconstruct and discuss the line of argument from TE to PIV and argue that our introspective intuitions (TE) do not push us in the direction of PIV. On the contrary, the line of argument from TE to PIV is (at best) simply too weak to force us to conclude that intentionality depends on phenomenal character in the sense required for PIV to be true. (shrink)

Externalism about colour phenomenology claims that the phenomenal character of colour experiences is determined by mind-independent properties of perceptual objects. The structural mismatch argument shows that physical properties of perceived mind-independent things are not similar in ways that correlate with the ways in which the phenomenal character of colour experiences are similar. Structural mismatch has thus been perceived by some to demonstrate that correlative externalism (which takes mind-independent physical properties to correlate systematically with colour phenomenology) is false. This argument is (...) defused if there are broad physical properties that can bear similarity relations that do correlate with those held by the phenomenal character of colour experiences. I defend the view that disjunctive properties can perform this role by showing that disjunctive properties can account for metamerism, the unique and binary hue distinction, and differences in perceived colours between subjects. Finally, I argue that correlative externalism is better placed than other views to explain why the physical properties identified by the physical sciences correlate with colour experiences with the particular phenomenal character they have. (shrink)

Many have suggested that, unlike the so-called higher-senses, the lower-senses are not capable of providing aesthetic experience. Supporting this is, what I will call, the Transparency-Exteroceptivity Argument, which says that a necessary feature for aesthetic experience is lacking in the case of the lower-senses, namely transparency/exteroceptivity. I argue, contrary to the Transparency-Exteroceptivity Argument, that olfaction can provide transparent access to the properties of particular external objects. I argue that the Transparency-Exteroceptivity Argument relies on a misleading visuocentric and unimodal view of (...) the senses, is guilty of hasty generalization, and should be rejected. (shrink)

Perceptual experience is often said to be transparent; that is, when we have a perceptual experience we seem to be aware of properties of the objects around us, and never seem to be aware of properties of the experience itself. This is a introspective fact. It is also often said that we can infer a metaphysical fact from this introspective fact, e.g. a fact about the nature of perceptual experience. A transparency theory fills in the details for these two facts, (...) and bridges the gap between them. We have three aims: to scrutinize Michael Tye’s transparency theory :137–151, 2002; Consciousness revisited: materialism without phenomenal concepts, MIT Press, Cambridge, 2009; Philos Stud 170:39–57, 2014a), introduce a new transparency theory, and advance a meta-theoretical hypothesis about the interest, and import, of transparency theories. (shrink)

The transparency of visual experience is a widely held and important thesis in the philosophy of perception. Critical discussion of transparency has focused on visual experiences, such as the experience of visual blur that are taken to be counter examples to transparency. Here, I consider a novel objection to transparency that does not depend on intuitions about examples. The objection is that if transparency is true then we cannot explain our ability to think about our visual experiences as such. In (...) response to this objection, I develop an account of how we are able to think about our own visual experiences as such that is compatible with transparency. (shrink)

This is a paper about The Causal Self-Referential Theory of Perception. According to The Causal Self-Referential Theory as developed by above all John Searle and David Woodruff Smith, perceptual content is satisfied by an object only if the object in question has caused the perceptual experience. I argue initially that Searle's account cannot explain the distinction between hallucination and illusion since it requires that the state of affairs that is presented in the perceptual experience must exist in order for the (...) perception to be veridical. Smith's account is interestingly different in that the descriptive content, i.e. the content that presents the perceptual object as having certain properties, does not determine the object of the experience. His account consequently does not require that the state of affairs that is presented in perception exists in order for the perception to have an object. Smith argues instead that perceptual reference is determined by a specific kind of demonstrative content. In this paper it is argued that Smith's account of demonstrative content is too indeterminate and in certain circumstances prescribes the wrong object. It is subsequently argued that the theory of demonstrative content can be modified so as to avoid these consequences. This modification involves deriving the conditions of satisfaction of seeing an object from the conditions of satisfaction of seeing the shape of the object, where the shape of the object is conceived of as a particularized property, what is also called a ‘trope’. (shrink)

A central topic in discussions about qualia concerns their purported transparency. According to transparency theorists, an experience is transparent in the sense that the subject having the experience is aware of nothing but the intended object of the experience. In this paper this notion is criticized for failing to account for the dynamical aspects of perception. A key assumption in the paper is that perceptual content has a certain temporal depth, in the sense that each act of perception can present (...) an object as extended in time and that objects can be perceived as persisting through time. An object that is seen as persisting through time is often seen as constant and unchanging, even though the presentation of it is changing. In this paper it is argued that in order to account for these cases of perceptual constancy, we must distinguish between the awareness of having perceived that an object has a property at a certain point in time, and perceptually intending that it has that property at that point in time. Consequently, we must in at least some instances be aware of something more than the object of the experience. But precisely this distinction is rejected by the transparency theory. (shrink)

This paper presents an ‘over-representational’ account of blurred visual experiences. The basic idea is that blurred experiences provide too much, inconsistent, information about objects’ spatial boundaries, by representing them as simultaneously located at multiple locations. This account attempts to avoid problems with alternative accounts of blurred experience, according to which blur is a property of a visual field, a way of perceiving, a form of mis-representation, and a form of under-representation.

Does inner sense, like outer sense, provide inner sensations or, in other words, a sensory manifold of its own? Advocates of the disparity thesis on inner and outer sense claim that it does not. This interpretation, which is dominant in the preexisting literature, leads to several inconsistencies when applied to Kant’s doctrine of inner experience. Yet, while so, the parity thesis, which is the contrasting view, is also unable to provide a convincing interpretation of inner sensations. In this paper, I (...) argue that this deadlock can be traced back to an inadequate understanding of inner sense shared by both sides. Drawing upon an analysis of the notion of obscure representations, I offer an alternative interpretation of inner sense with a special regard to self-affection, apprehension, and attention. From this basis, I will infer that outer sense delivers sensory content that is initially and intrinsically unaccompanied by phenomenal consciousness; inner sense contributes by endowing such content with phenomenal consciousness. Therefore, phenomenal qualities can be regarded as the sensory manifold of inner sense. This alternative interpretation solves the long-standing dispute concerning inner sensations and would further illuminate Kant’s notion of inner experience. (shrink)

A satisfactory solution to the problem of consciousness would take the form of a simple yet fully general model that specifies the precise conditions under which any given state of consciousness occurs. Science has uncovered numerous correlations between consciousness and neural activity, but it has not yet come anywhere close to this. We are still looking for the Newtonian laws of consciousness. -/- One of the main difficulties with consciousness is that we lack a language in which to formulate illuminating (...) generalizations about it. Philosophers and scientists talk about "what it’s like", sensations, feelings, and perceptual states such as seeing and hearing. This language does not allow a precise articulation of the internal structures of conscious states and their inter-relations. It is inadequate to capture relations of the kind we are looking for between conscious states and physical states. -/- In this thesis I refine and defend a theory of consciousness which promises to solve this regimentation problem: the representational theory of consciousness. I argue that the representational theory can solve the regimentation problem and smooth out other important obstacles to a fruitful study of consciousness. I also make a case for the theory independently of its payoffs, and I discuss the leading opposing theories at some length. (shrink)