Recently, the thesis that experience is fundamentally a matter of representing the world as being a certain way has been questioned by austere relationalists. I defend this thesis by developing a view of perceptual content that avoids their objections. I will argue that on a relational understanding of perceptual content, the fundamental insights of austere relationalism do not compete with perceptual experience being representational. As it will show that most objections to the thesis that experience has content apply only to (...) accounts of perceptual content on which perceptual relations to the world play no explanatory role. With austere relationalists, I will argue that perceptual experience is fundamentally relational. But against austere relationalists, I will argue that it is fundamentally both relational and representational. (shrink)

What makes an object the same persisting individual over time? Philosophers and psychologists have both grappled with this question, but from different perspectives—philosophers conceptually analyzing the criteria for object persistence, and psychologists exploring the mental mechanisms that lead us to experience the world in terms of persisting objects. It is striking that the same themes populate explorations of persistence in these two very different fields—e.g. the roles of spatiotemporal continuity, persistence through property change, and cohesion violations. Such similarities may reflect (...) an underlying connection, in that psychological mechanisms of object persistence (especially relevant parts of mid-level visual object processing) may serve to underlie the intuitions about persistence that fuel metaphysical theories. This would be a way for cognitive science to join these two disparate fields, helping to explain the possible origins and reliability of some metaphysical intuitions, and perhaps leading to philosophical progress. (shrink)

One of the more powerful impressions created by vision is that of a coherent, richly-detailed world where everything is present simultaneously. Indeed, this impression is so compelling that we tend to ascribe these properties not only to the external world, but to our internal representations as well. But results from several recent experiments argue against this latter ascription. For example, changes in images of real-world scenes often go unnoticed when made during a saccade, flicker, blink, or movie cut. This "change (...) blindness" provides strong evidence against the idea that our brains contain a picture-like representation of the scene that is everywhere detailed and coherent. (shrink)

I am very grateful to my commentators for their interest and their careful attention to A Theory of Sentience. It is particularly gratifying to find other philosophers attracted to the murky domain of pre-attentive sensory processing, an obscure place where exciting stuff happens. I can by no means answer all of their objections or counter-arguments, and some of the problems noted derive from failures in my original exposition. But a theory is a success if it helps spur the creation of (...) better successors. By those lights this one seems to be succeeding admirably. Would that every author could receive such commentaries! (shrink)

This paper argues that a theory of situated vision, suited for the dual purposes of object recognition and the control of action, will have to provide something more than a system that constructs a conceptual representation from visual stimuli: it will also need to provide a special kind of direct (preconceptual, unmediated) connection between elements of a visual representation and certain elements in the world. Like natural language demonstratives (such as `this' or `that') this direct connection allows entities to be (...) referred to without being categorized or conceptualized. Several reasons are given for why we need such a preconcep- tual mechanism which individuates and keeps track of several individual objects in the world. One is that early vision must pick out and compute the relation among several individual objects while ignoring their properties. Another is that incrementally computing and updating representations of a dynamic scene requires keeping track of token individuals despite changes in their properties or locations. It is then noted that a mechanism meeting these requirements has already been proposed in order to account for a number of disparate empiri- cal phenomena, including subitizing, search-subset selection and multiple object tracking (Pylyshyn et al., Canadian Journal of Experimental Psychology 48(2) (1994) 260). This mechanism, called a visual index or FINST, is brie. (shrink)

In this book I address a dichotomy that is as central as any in ontology - that between ordinary objects or substances and the various attributes (Le., properties, kinds, and relations) we associate with them. My aim is to arrive at the correct philosophical account of each member of the dichotomy. What I shall argue is that the various attempts to understand substances or attri butes in reductive terms fail. Talk about attributes, I shall try to show, is just that (...) - talk about attributes; and, likewise, talk about substances is just tha- talk about substances. The result is what many will find a strange combina tion of views - a Platonistic theory of attributes, where attributes are univer sals or multiply exemplifiable entities whose existence is independent of "the world of flux", and an Aristotelian theory of substance, where substances are basic unities not reducible to metaphysically more fundamental kinds of things. Part One is concerned with the ontology of attributes. After distinguishing three different patterns of metaphysical thinking about attributes, I examine, in turn, the phenomena of predication, resemblance, and higher order quanti fication. I argue that none of these phenomena by itself is sufficient to establish the inescapability of a Platonistic interpretation of attributes. Then, I discuss the phenomenon of abstract reference as it is exhibited in the use of abstract singular terms. (shrink)

In "Things and Places," Zenon Pylyshyn argues that the process of incrementally constructing perceptual representations, solving the binding problem (determining which properties go together), and, more generally, grounding perceptual ...

This article considers reasons for and reasons against postulating substrata in ontology, and argues that the case against amounts to a refutation.

In Clark (2000), Austen Clark argues convincingly that a widespread view of perception as a complicated kind of feature-extraction is incomplete. He argues that perception has another crucial representational ingredient: it must also involve the representation of "sensory individuals" that exemplify sensorily extracted features. Moreover, he contends, the best way of understanding sensory individuals takes them to be places in space surrounding the perceiver. In this paper, I'll agree with Clark's case for sensory individuals (.

v. 1. Nominalism and realism.--v. 2. A theory of universals.

How do we know what we "know"? How did we –as individuals and as a society – come to accept certain knowledge as fact? In _Human Knowledge,_ Bertrand Russell questions the reliability of our assumptions on knowledge. This brilliant and controversial work investigates the relationship between ‘individual’ and ‘scientific’ knowledge. First published in 1948, this provocative work contributed significantly to an explosive intellectual discourse that continues to this day.

Both and agree that there are universals—that qualities are universals. To say that the quality white is a universal is to say, in part, that one and the same thing is connected in some way to both Plato and Socrates and accounts for the truth of the sentences "Plato is white" and "Socrates is white." To put it another way, the term "white" in both sentences refers to the same entity. What arguments are there for such a view? Russell elegantly (...) put forth the classic argument in "On the Relations of Universals to Particulars." To deny universals is to assert that the quality attributed to Socrates is not one and the same with the quality attributed to Plato. The quality "in" each is numerically distinct and, furthermore, no one thing accounts for these distinct qualities being of the same kind. [I mention this latter point since one might, on a version of, hold that there are particular qualities as well as universal qualities. The former account for the whiteness of particular patches; the latter for such particular whitenesses being just that.] One must then hold that such particular qualities are related in some way, since they are the entities in virtue of which we truly assert that both things are white. One must then specify such a relation. The obvious point is that such a relation will either be taken as a universal or a particular instance. If a particular then the original problem recurs when we introduce a third white patch or a pair of black patches. If admitted as a universal then the view finally accepts universals, albeit relational ones. No other alternative can answer the original question—to account for Socrates and Plato having the same color. That is, no alternative acknowledging only individuals—that denies the two patches are connected, in some way, to one and the same entity—can prevent the recurrence of exactly the same kind of question we started out with. Let us consider the case of particulars. One may argue that just as universals account for the sameness of quality, something must account for the difference of two patches which, conceivably, have all their nonrelational qualities in common. This something, the ground of numerical difference, is considered to be a substratum which stands in a unique relation or connection with universals to form or constitute facts and the things we started out with, Plato and Socrates. These ordinary things are thought of as composed of a substratum and universals connected together. Facts about such things may be composed of the substratum and one universal. The facts are about the things since the same substratum is a constituent of both sorts of entities. Such substrata account for the difference of the two patches; for there being two and not one thing. These substrata, in turn, are held to be simply different. At this point one may balk. If substrata are held to be simply different, why bother with them at all? Why not hold that Socrates and Plato are composites, not classes, of universals, and that they are different composites of the same universals? They just simply differ. If substrata can simply differ, why may not composites of universals simply differ? The proponent of substrata must retort that since Plato and Socrates are composite entities they cannot simply differ but must be held to differ in a constituent. Only simple entities can simply differ. Let me call this assertion the axiom of difference. The first point to note is that it is a necessary assumption in the argument to establish the need for substrata in an adequate ontology. We must then inquire why some accept, implicitly or explicitly, such an axiom. (shrink)

This textbook on vision reflects the integrated computational approach of modern research scientists, combining psychological, computational and neuroscientific perspectives.

ACCORDING TO DUNS SCOTUS, what makes a material substance an individual is a positive entity which falls within the category of substance and contracts the specific nature to this or that. That entity, called haecceitas, together with the formal distinction, constitutes the core of Scotus' theory of individuation. But what is haecceitas? Haecceitas is not definable. Nor can we be acquainted with it. Then how could we understand it? Both negatively and positively, Scotus himself tried to give an answer to (...) this question. Before presenting his haecceitas theory, Scotus criticized six different types of rival theories available in his day: the position of the nominalists, the double negation theory, the theory of individuation by actual existence, the theory of individuation by quantity or other accidents, the theory of individuation by matter, and the theory attributed to Godfrey of Fontaines. In other words, he was explaining "what haecceitas is not" when he criticized these theories. More importantly, he tried to give us a positive characterization of haecceitas. Since he used "individual difference" as a synonym for "haecceitas," he resorted to an analogy between the specific difference and the individual difference in order to explain the notion of haecceitas. The problem is that twentieth-century ontologists may not be patient enough to study the triple analogy, which again presupposes Scotus' doctrines of the formal distinction and the ultimate difference. In order to draw their attention to Scotus' theory of individuation, one would need to discuss the following questions: How can we translate the term "haecceitas" into modern terminology? Is there any counterpart of haecceitas in contemporary ontology? For what reasons should we reintroduce haecceitas into the current discussion of individuation, if it has a good counterpart? Is there still anything significant left to add to our understanding of haecceitas? (shrink)

In three experiments, subjects attempted to track multiple items as they moved independently and unpredictably about a display. Performance was not impaired when the items were briefly (but completely) occluded at various times during their motion, suggesting that occlusion is taken into account when computing enduring perceptual objecthood. Unimpaired performance required the presence of accretion and deletion cues along fixed contours at the occluding boundaries. Performance was impaired when items were present on the visual field at the same times and (...) to the same degrees as in the occlusion conditions, but disappeared and reappeared in ways which did not implicate the presence of occluding surfaces (e.g. by imploding and exploding into and out of existence, instead of accreting and deleting along a fixed contour). Unimpaired performance did not require visible occluders (i.e. Michotte’s tunnel effect) or globally consistent occluder positions. We discuss implications of these results for theories of objecthood in visual attention. (shrink)