Discriminability

[Working Draft — Comments are welcome! — March 2024] Reductive strong representationalists accept the Common Kind Thesis about subjectively indistinguishable sensory hallucinations, illusions, and veridical experiences. I show that this doesn’t jibe well with their declared phenomenal externalism and argue that there is no sense in which the phenomenal character of sensory experiences is constituted by the sensible properties represented by these experiences, as representationalists claim. First, I argue that, given general representationalist principles, no instances of a sensible property constitute (...) the phenomenal character of the sensory experience that represents them. Second, I argue that, with two very plausible assumptions in place, no sensible property qua universal can constitute the phenomenal character of experiences either. At the end, I offer an alternative picture that is consistent with a naturalist psychosemantics for sensory experiences without embracing phenomenal externalism. (shrink)

Our main aims in this paper is to discuss and criticise the core thesis of a position that has become known as phenomenal conservatism. According to this thesis, its seeming to one that p provides enough justification for a belief in p to be prima facie justified (a thesis we label Standard Phenomenal Conservatism). This thesis captures the special kind of epistemic import that seemings are claimed to have. To get clearer on this thesis, we embed it, first, in a (...) probabilistic framework in which updating on new evidence happens by Bayesian conditionalization, and second, a framework in which updating happens by Jeffrey conditionalization. We spell out problems for both views, and then generalize some of these to non-probabilistic frameworks. The main theme of our discussion is that the epistemic import of a seeming (or experience) should depend on its content in a plethora of ways that phenomenal conservatism is insensitive to. (shrink)

You can demonstrate a subjective quality like redness is different from red light. If you add a device that converts a red signal into a green one, between the retina and the optic nerve, the strawberry will seem green. It’s not about light hitting the retina, it’s about how the signal is processed. In this case, the greenness must be a quality of our conscious knowledge of the strawberry, not of the red light landing on the retina. If you use (...) sufficient, well defined terminology, you can objectively communicate the nature of subjective qualities. For example, even though you know what it is like to see something that is red you cannot know that what happens inside my brain is the same as yours. It may be that “My redness is like your greenness, both of which we call red.” The properties of the red light are the same, but the experience the light produces could be different. What we lack is a universal dictionary to define what “redness” is, and how it differs from “red”. This is because physicists can’t yet answer: “Which of all our descriptions of stuff in the brain, including possible descriptions of yet unknown processes, is a description of redness?” Consciousness isn’t a ‘hard problem’ it is a color problem. Because if you understand color, that model of computation can extend to the rest of consciousness. (shrink)

In this paper, I argue for phenomenology, Husserlian phenomenology to be precise, as providing a solid paradigm on how to determine and assess hallucination. To be more explicit, in the context of my deliberations, I analyze Susanna Schellenberg’s arguments for “phenomenal” evidence and “factive” evidence, as regards her evidential theory of perception. To pinpoint the inadequacies raised in her account of (the hallucinating) Hallie and (the veridically perceiving) Percy sharing any kind of evidence, I propose Edmund Husserl’s epistemic fulfillment as (...) a detailed epistemological analysis of perception, which takes into consideration the latter’s phenomenological complexity. (shrink)

A central objection to McDowell’s conceptualism about empirical content concerns the fine-grained phenomenology of experience, which supposedly entails that the actual content of experience cannot be matched in its particularity by our concepts. While McDowell himself has answered this objection in recourse to the possibility of demonstrative concepts, his reply has engendered a plethora of further objections and is widely considered inadequate. I believe that McDowell’s critics underestimate the true force of his reply because they tend to read unrecognized empiricist (...) presuppositions into his account of experience. To show this, I introduce a new hylomorphic reading of McDowell’s account of experience and argue that the objections to his reply all rest on a specific empiricist assumption, which is untenable because it conflates the form of experience with its content. Consequently, conceptualism so understood can resist all of these objections, as I attempt to show by systematizing and answering them. (shrink)

Consciousness and confidence seem intimately related. Accordingly, some researchers use confidence ratings as a measure of, or proxy for, consciousness. Rosenthal discusses the potential connections between the two, and rejects confidence as a valid measure of consciousness. He argues that there are better alternatives to get at conscious experiences such as direct subjective reports of awareness (i.e. subjects’ reports of perceiving something or of the degree of visibility of a stimulus). In this chapter, we offer a different perspective. Confidence ratings (...) in general, and metacognitive measures in particular, may offer important advantages over subjective ratings. The arguments we offer here are supported by empirical, practical and socio-strategic considerations. However, we do not suggest consciousness and confidence are interchangeable. We recognize the limitations of confidence ratings in some experimental designs and for some research questions. Nevertheless, we also address a potential conceptual link between consciousness and confidence that stems from Rosenthal’s very own work on mental quality space theory. (shrink)

According to capacitism, to perceive is to employ personal-level, perceptual capacities. In a series of publications, Schellenberg (2016, 2018, 2019b, 2020) has argued that capacitism offers unified analyses of perceptual particularity, perceptual content, perceptual consciousness, perceptual evidence, and perceptual knowledge. “Capacities first” (2020: 715); appealing accounts of an impressive array of perceptual and epistemological phenomena will follow. We argue that, given the Schellenbergian way of individuating perceptual capacities which underpins the above analyses, perceiving an object does not require employing a (...) perceptual capacity which picks it out. Although each eye, used on its own, can suffice for perceiving objects in one’s environment, binocular vision allows one to see the same object(s) via both eyes, taking advantage of informational disparities registered by each eye. Yet in certain conditions it is possible to simultaneously see one object via the left eye and a distinct object via the right eye (at least when the inputs are sufficiently similar to prevent the onset of binocular rivalry). We argue that capacitism has trouble making sense of this. After surveying responses, we conclude that not all of the above phenomena can be unified under the capacitist framework. We then present a more nuanced, disjunctivist account of how capacities are individuated. While it may be illuminating to think of perceiving as the employment of perceptual capacities, this picture does not best favour a ‘common factor’ theory of perceptual content in the way existing presentations have envisaged. (shrink)

Four experiments investigated the extent to which abstract quantitative information can be conveyed by basic visual features. This was done by asking observers to estimate and discriminate Pearson correlation in graphical representations where the first data dimension of each element was encoded by its horizontal position, and the second by the value of one of its visual features; perceiving correlation then requires combining the information in the two encodings via a common abstract representation. Four visual features were examined: luminance, color, (...) orientation, and size. All were able to support the perception of correlation. Indeed, despite the strikingly different appearances of the associated stimuli, all gave rise to performance that was much the same: just noticeable difference was a linear function of distance from complete correlation, and estimated correlation a logarithmic function of this distance. Performance differed only in regards to the level of noise in the feature, with these values compatible with estimates of channel capacity encountered in classic experiments on absolute perceptual magnitudes. These results suggest that quantitative information can be conveyed by visual features that are abstracted at relatively low levels of visual processing, with little representation of the original sensory property. It is proposed that this is achieved via an abstract parameter space in which the values in each perceptual dimension are normalized to have the same means and variances, with perceived correlation based on the shape of the joint probability density function of the resultant elements. (shrink)

In this paper I claim that perceptual discriminatory skills rely on a suitable type of environment as an enabling condition for their exercise. This is because of the constitutive connection between environment and perceptual discriminatory skills, inasmuch as such connection is construed from an ecological approach. The exercise of a discriminatory skill yields knowledge of affordances of objects, properties, or events in the surrounding environment. This is practical knowledge in the first-person perspective. An organism learns to perceive an object by (...) becoming sensitized to its affordances. I call this position ecological disjunctivism. A corollary of this position is that a case of perception and its corresponding case of hallucination—which is similar to the former only in some respects—are different in nature. I show then how the distinguishability problem is addressed by ecological disjunctivism. (shrink)

Internalism and externalism disagree about whether agents who are internally the same can differ in their mental states. But what is it for two agents to be internally the same? Standard formulations take agents to be internally the same in virtue of some metaphysical fact, for example, that they share intrinsic physical properties. Our aim in this chapter is to argue that such formulations should be rejected. We provide the outlines of an alternative formulation on which agents are internally the (...) same in virtue of facts about their epistemic capacities. The resulting formulation is one on which internalism and externalism are views about the extent to which an agent’s mental states can vary independently of the capacity for introspective discrimination. We suggest that this epistemic formulation of internalism and externalism picks out a substantive disagreement in philosophical theorizing about the nature of the mind. (shrink)

Conscious experiences are characterized by mental qualities, such as those involved in seeing red, feeling pain, or smelling cinnamon. The standard framework for modeling mental qualities represents them via points in geometrical spaces, where distances between points inversely correspond to degrees of phenomenal similarity. This paper argues that the standard framework is structurally inadequate and develops a new framework that is more powerful and flexible. The core problem for the standard framework is that it cannot capture precision structure: for example, (...) consider the phenomenal contrast between seeing an object as crimson in foveal vision versus merely as red in peripheral vision. The solution I favor is to model mental qualities using regions, rather than points. I explain how this seemingly simple formal innovation not only provides a natural way of modeling precision, but also yields a variety of further theoretical fruits: it enables us to formulate novel hypotheses about the space and structures of mental qualities, formally differentiate two dimensions of phenomenal similarity, generate a quantitative model of the phenomenal sorites, and define a measure of discriminatory grain. A noteworthy consequence is that the structure of the mental qualities of conscious experiences is fundamentally different from the structure of the perceptible qualities of external objects. (shrink)

The debate between relationalism and representationalism in the philosophy of perception seems to have come to a standstill where opponents radically disagree on methodological principles or fundamental assumptions. According to Fish (this volume) this is because, not unlike Kuhnian scientific paradigms, the debate displays some elements of incommensurability. This diagnosis makes advancing the debate impossible. I argue that what is hindering progress is not a clash of research programmes, but a series of misunderstandings that can be avoided by disentangling the (...) different questions each theory is invested in and by making explicit the hidden assumptions at play in the debate. One such central assumption is what I call the Superficiality Constraint. This is the idea that the phenomenal character of experience is superficial with respect to introspection. I argue that we can make progress in the debate by assessing to what extent and at what cost relationalism can accommodate this constraint. (shrink)

Discrimination is a central epistemic capacity but typically, theories of discrimination only use discrimination as a vehicle for analyzing knowledge. This paper aims at developing a self-contained theory of discrimination. Internalist theories of discrimination fail since there is no compelling correlation between discriminatory capacities and experiences. Moreover, statistical reliabilist theories are also flawed. Only a modal theory of discrimination is promising. Versions of sensitivity and adherence that take particular alternatives into account provide necessary and sufficient conditions on discrimination. Safety in (...) contrast is not sufficient for discrimination as there are cases of safety that are clearly instances of discrimination failure. The developed account of discrimination between objects will be extended to discrimination between kinds and between types. (shrink)

In this paper, I raise an objection to Philip Goff’s “Revelation Thesis” as articulated in his Consciousness and Fundamental Reality. In Sect. 1 I present the Revelation Thesis in the context of Goff’s broader defence of pan-psychism. In Sect. 2 I argue that the Revelation Thesis entails the identity of indiscriminable phenomenal properties. In Sect. 3 I argue that the identity of indiscriminable phenomenal properties is false. The upshot is that the Revelation Thesis is false.

In this chapter, I put forward and sustain an articulation of the notion of bodily skill based on ecological psychology, and I show how it is relevant for the debate between Dreyfus and McDowell about skillful coping and also for the debate about whether know-how is reducible or not to propositional knowledge. The right metaphor to understand bodily skills is not the computer metaphor but the radio metaphor. These skills result from a process of organism attunement to its environment.

Carter and Pritchard (2016) and Pritchard (2010, 2012, 2016) have tried to reconcile the intuition that perceptual knowledge requires only limited discriminatory abilities with the closure principle. To this end, they have introduced two theoretical innovations: a contrast between two ways of introducing error-possibilities and a distinction between discriminating and favoring evidence. I argue that their solution faces the “sufficiency problem”: it is unclear whether the evidence that is normally available to adult humans is sufficient to retain knowledge of the (...) entailing proposition and come to know the entailed proposition. I submit that, on either infallibilist or fallibilist views of evidence, Carter and Pritchard have set the bar for deductive knowledge too low. At the end, I offer an alternative solution. I suggest that the knowledge-retention condition of the closure principle is not satisfied in zebra-like scenarios. (shrink)

As a philosophical paradigm, differential heterogenesis offers us a novel descriptive vantage with which to inscribe Deleuze’s virtuality within the terrain of “differential becoming,” conjugating “pure saliences” so as to parse economies, microhistories, insurgencies, and epistemological evolutionary processes that can be conceived of independently from their representational form. Unlike Gestalt theory’s oppositional constructions, the advantage of this aperture is that it posits a dynamic context to both media and its analysis, rendering them functionally tractable and set in relation to other (...) objects, rather than as sedentary identities. Surveying the genealogy of differential heterogenesis with particular interest in the legacy of Lautman’s dialectic, I make the case for a reading of the Deleuzean virtual that departs from an event-oriented approach, galvanizing Sarti and Citti’s dynamic a priori vis-à-vis Deleuze’s philosophy of difference. Specifically, I posit differential heterogenesis as frame with which to examine our contemporaneous epistemic shift as it relates to multi-scalar computational modeling while paying particular attention to neuro-inferential modes of inductive learning and homologous cognitive architecture. Carving a bricolage between Mark Wilson’s work on the “greediness of scales” and Deleuze’s “scales of reality”, this project threads between static ecologies and active externalism vis-à-vis endocentric frames of reference and syntactical scaffolding. (shrink)

In 1688 the Irish scientist and politician William Molyneux sent a letter to the philosopher John Locke. In it, he asked him a question: could someone who was born blind, and able to distinguish a globe and a cube by touch, be able to immediately distinguish and name these shapes by sight if given the ability to see? -/- The philosophical puzzle offered in Molyneux’s letter fascinated not only Locke, but major thinkers such as Leibniz, Berkeley, Diderot, Reid, and numerous (...) others including psychologists and cognitive scientists today. Does such a question represent a philosophical puzzle or a problem that can be solved by experimental tests? Can vision be fully restored after blindness? What is the relation between vision and touch? Are the senses linked through learning or bound at birth? -/- Molyneux’s Question and the History of Philosophy is a major collection of essays that explore the long-standing issues Molyneux’s problem presents to philosophy of mind, perception and the senses. In addition, the volume considers the question from an interdisciplinary angle, examines the pre-history of the question, and aspects of it that have been ignored, such as perspectives from religion and disability. -/- As such, Molyneux’s Question and the History of Philosophy presents a set of philosophically rich, empirically informed, and scientifically rigorous original investigations into this famous puzzle. It will be of great interest to students and researchers in philosophy, psychology, and the cognitive sciences including neuroscience, neurobiology and ophthalmology, as well as those studying the mind, perception and the senses. (shrink)

It is tempting to think that one’s perceptual evidence comprises just what issues from perceiving with each of the respective sensory modalities. However, empirical, rational, and phenomenological considerations show that one’s perceptual evidence can outstrip what one possesses due to perceiving with each separate sense. Some novel perceptual evidence stems from the coordinated use of multiple senses. This paper argues that some perceptual evidence in this respect is distinctively multisensory.

According to a certain kind of naïve or folk understanding of physical matter, everyday ‘solid’ objects are composed of a homogeneous, gap-less substance, with sharply defined boundaries, which wholly fills the space they occupy. A further claim is that our perceptual experience of the environment represents or indicates that the objects around us conform to this sort of conception of physical matter. Were this further claim correct, it would mean that the way that the world appears to us in experience (...) conflicts with the deliverances of our best current scientific theories in the following respect: perceptual experience would be intrinsically misleading concerning the structure of physical matter. I argue against this further claim. Experience in itself is not committed to, nor does it provide evidence for, any such conception of the nature of physical matter. The naïve/folk conception of matter in question cannot simply be ‘read-off’ from perceptual appearances. (shrink)

Does the scope of beliefs that people can form on the basis of perception remain fixed, or can it be amplified with learning? The answer to this question is important for our understanding of why and when we ought to trust experts, and also for assessing the plausibility of epistemic foundationalism. The empirical study of perceptual expertise suggests that experts can indeed enrich their perceptual experiences through learning. Yet this does not settle the epistemic status of their beliefs. One might (...) hold that the background knowledge of experts is the cause of their enriched perceptual experience – what is known as cognitive permeation – and so their subsequent beliefs are only mediately justified because they are epistemically dependent on this background knowledge. I argue against this view. Perceptual expertise is not the result of cognitive permeation but is rather the result of perceptual learning, and perceptual learning does not involve cognition in a way that entails cognitive permeation. Perceptual expertise thus provides a means of widening the scope of the immediately justified beliefs that experts can form. (shrink)

Many of our sources of knowledge only afford us knowledge that is inexact. When trying to see how tall something is, or to hear how far away something is, or to remember how long something lasted, we may come to know some facts about the approximate size, distance or duration of the thing in question but we don’t come to know exactly what its size, distance or duration is. In some such situations we also have some pointed knowledge of how (...) inexact our knowledge is. That is, we can knowledgeably pinpoint some exact claims that we do not know. We show that standard models of inexact knowledge leave little or no room for such pointed knowledge. We devise alternative models that are not afflicted by this shortcoming. (shrink)

In "The Epistemic Significance of Perceptual Learning," Elijah Chudnoff (this issue) argues that cases from perceptual learning show that perception not only generates reasons for beliefs but also preserves those reasons over time in perceptual learning cases. In this paper, we dispute the idea that perceptual learning enables the preservation of perceptual reasons. We then argue for an alternative view, viz. the view that perceptual learning is epistemically significant insofar as it modifies our perceptual system in such a way as (...) to make us capable of perceiving subtle low-level properties (e.g. lightness) and high-level properties (e.g. chess configurations). Acquiring the capacity to perceive these properties is what enables us to achieve expertise in a variety of subject matters (e.g. chicken sexing, chess playing, language fluency). Along the way, we argue against two main points in Chudnoff’s paper. The first is that, pace Chudnoff, perceptual learning does not result in the acquisition of new facts. It only results in the acquisition of a new perceptual capacity. The second is that experiences resulting from perceptual learning can always serve as immediate justifiers of beliefs and hence do not need supporting background information in order to serve as reasons. (shrink)

In his book “Seeing Dark Things” (2008), Roy Sorensen provides many wonderfully ingenious arguments for many surprising, counter-intuitive claims. One such claim in particular is that when we a silhouetted object – i.e. an opaque object lit entirely from behind – we literally see its back-side – i.e. we see the full expanse of the surface facing away from us that is blocking the incoming light. Sorensen himself admits that this seems a tough pill to swallow, later characterising it as (...) “the most controversial thesis of the book” (2011, p199). -/- I will argue against Sorensen’s controversial thesis and in favour of what seems to me to be a much more natural and commonsensical alternative: when we see a silhouetted object, what we see is its edge and only its edge – so we do not see its entire back-side. (shrink)

Epistemological Disjunctivism is a view about paradigm cases of perceptual knowledge. Duncan Pritchard claims that it is particularly well suited to accounting for internalist and externalist intuitions. A number of authors have disputed this claim, arguing that there are problems for Pritchard’s way with internalist intuitions. I share the worry. However, I don’t think it has been expressed as effectively as it can be. My aim in this paper is to present a new way of formulating the worry, in terms (...) of an “explanatory challenge”. The explanatory challenge is a simple, yet powerful and illuminating challenge for Epistemological Disjunctivism. It is illuminating in the sense that it shows us why Epistemological Disjunctivism must take on certain internalistically problematic commitments. A secondary aim of this paper is to examine whether the recently much-discussed distinction between justifications and excuses in epistemology can support an adequate response. I will argue that it cannot. (shrink)

For scatterplots with gaussian distributions of dots, the perception of Pearson correlation r can be described by two simple laws: a linear one for discrimination, and a logarithmic one for perceived magnitude (Rensink & Baldridge, 2010). The underlying perceptual mechanisms, however, remain poorly understood. To cast light on these, four different distributions of datapoints were examined. The first had 100 points with equal variance in both dimensions. Consistent with earlier results, just noticeable difference (JND) was a linear function of the (...) distance away from r = 1, and the magnitude of perceived correlation a logarithmic function of this quantity. In addition, these laws were linked, with the intercept of the JND line being the inverse of the bias in perceived magnitude. Three other conditions were also examined: a dot cloud with 25 points, a horizontal compression of the cloud, and a cloud with a uniform distribution of dots. Performance was found to be similar in all conditions. The generality and form of these laws suggest that what underlies correlation perception is not a geometric structure such as the shape of the dot cloud, but the shape of the probability distribution of the dots, likely inferred via a form of ensemble coding. It is suggested that this reflects the ability of observers to perceive the information entropy in an image, with this quantity used as a proxy for Pearson correlation. (shrink)

Based on Pritchard’s distinction (2012, 2016) between favoring and discriminating epistemic grounds, and on how those grounds bear on the elimination of skeptical possibilities, I present the dream argument as a moderate skeptical possibility that can be reasonably motivated. In order to block the dream argument skeptical conclusion, I present a version of phenomenological disjunctivism based on Noë’s actionist account of perceptual consciousness (2012). This suggests that perceptual knowledge is rationally grounded because it is a form of embodied achievement – (...) what I call embodied rationality –, which offers a way of dissolving the pseudo-problem of epistemic immodesty, namely, the seemingly counterintuitive thesis that one can acquire rationally grounded knowledge that one is not in a radical skeptical scenario. (shrink)

Planar geometry was exploited for the computation of symmetric visual curves in the image plane, with consistent variations in local parameters such as sagitta, chordlength, and the curves’ height-to-width ratio, an indicator of the visual area covered by the curve, also called aspect ratio. Image representations of single curves (no local image context) were presented to human observers to measure their visual sensation of curvature magnitude elicited by a given curve. Nonlinear regression analysis was performed on both the individual and (...) the average data using two types of model: (1) a power function where. (shrink)

Naive realists hold that experience is to be understood in terms of an intimate perceptual relation between a subject and aspects of the world, relative to a certain standpoint. Those aspects of the world themselves shape the contours of consciousness. But blurriness is an aspect of some of our experiences that does not seem to come from the world. I argue that this constitutes a significant challenge to some forms of naive realism. But I also argue that there is a (...) robust form of naive realism which is unfazed by the blurriness of some of our experiences, even when that blurriness is understood as a subjective modification of consciousness. (shrink)

In this paper I show that a variety of Cartesian Conceptions of the mental are unworkable. In particular, I offer a much weaker conception of limited discrimination than the one advanced by Williamson (2000) and show that this weaker conception, together with some plausible background assumptions, is not only able to undermine the claim that our core mental states are luminous (roughly: if one is in such a state then one is in a position to know that one is) but (...) also the claim that introspection is infallible with respect to our core mental states (where a belief that C obtains is infallible just in case if one believes that C obtains then C obtains). The upshot is a broader and much more powerful case against the Cartesian conception of the mental than has been advanced hitherto. (shrink)

The goal of the present paper is to defend against a certain line of attack the view that conscious experience of color is no more fine-grained that the repertoire of non- demonstrative concepts that a perceiver is able to bring to bear in perception. The line of attack in question is an alleged empirical argument - the Diachronic Indistinguishability Argument - based on pairs of colors so similar that they can be discriminated when simultaneously presented but not when presented across (...) a memory delay. My aim here is to show that this argument fails. (shrink)

This is a paper about a general representational theory of consciousness. It is quite old, and much progress has been made since. We are building and tracking consensus arround the ideas in the Representational Qualia Theory camp on Canonizer.

According to the Ability Hypothesis, knowing what it is like to have experience E is just having the ability to imagine or recognize or remember having experience E. I examine various versions of the Ability Hypothesis and point out that they all face serious objections. Then I propose a new version that is not vulnerable to these objections: knowing what it is like to experience E is having the ability to discriminate imagining or having experience E from imagining or having (...) any other experience. I argue that if we replace the ability to imagine or recognize with the ability to discriminate, the Ability Hypothesis can be salvaged. (shrink)

Abstract: How exactly should the relation between a veridical perception and a corresponding hallucination be understood? I argue that the epistemic notion of ‘indiscriminability’, understood as lacking evidence for the distinctness of things, is not suitable for defining this relation. Instead, we should say that a hallucination and a veridical perception involve the same phenomenal properties. This has further consequences for attempts to give necessary and sufficient conditions for the identity of phenomenal properties in terms of indiscriminability, and for considerations (...) about the phenomenal sorites. (shrink)

In this initially daunting but ultimately enjoyable and informative book, Mohan Matthen argues that this tradition is mistaken about both the processes of perception or sensing and the relationship between sensation, perception, and cognition. Since this tradition is sufficiently alive and well in the contemporary literature to constitute something like the received view of perception and the role of sensation in it, Matthen’s challenge and the alternative view he proposes are potentially significant. Sensory systems, Matthen thinks, are primarily devices for (...) sorting objects into kinds, a process resulting in sensory quality spaces that provide the basis for judgments about and inductions over what there is in the world perceived. Sensory systems do not deliver ‘raw’ sense data, fleeting qualia, or unordered sensations for true cognitive processing; rather, they deliver an output that is sorted and ordered, an output that is already, in traditional terms, conceptualized. Sensory experience or sensations come not ‘before’ cognition but ‘after’ it. When we think about sensory systems in general, and not just the small subset of them that we possess, sensory experience is thus a kind of icing on the cake of perception, not one of its crucial ingredients. (shrink)

The two kinds of discrimination I want to talk about are political discrimination and cognitive discrimination. By political discrimination, I mean what we ordinarily understand by the term "discrimination" in political contexts: A manifest attitude in which a particular property of a person which is irrelevant to judgments of that person's intrinsic value or competence, for example his race, gender, class, sexual orientation, or religious or ethnic affiliation, is seen as a source of disvalue or incompetence; in general, as a (...) source of inferiority.By cognitive discrimination, I mean what we ordinarily understand by the term "discrimination" in cognitive contexts: A manifest capacity to distinguish veridically between one property and another, and to respond appropriately to each. I want to explore the relation between these two kinds of discrimination, and to argue that the first type of discrimination depends upon a failure of the second. (shrink)

Spatial facilitation has been observed with luminance-defined, achromatic stimuli on achromatic backgrounds as well as with targets and inducers defined by colour contrast. This paper reviews psychophysical results from detection experiments with human observers showing the conditions under which spatially separated contour inducers facilitate the detection of simultaneously presented target stimuli. The findings point towards two types of spatial mechanisms: (i) Short-range mechanisms that are sensitive to narrowly spaced stimuli of small size and, at distinct target locations, selective to the (...) contrast polarity of targets and inducers. (ii) Long-range mechanisms that are triggered by longer stimuli, generate facilitation across wider spatial gaps between targets and inducers, and are insensitive to their contrast polarity. Spatial facilitation with chromatic stimuli requires a longer inducer exposure than spatial facilitation with achromatic stimuli, which is already fully effective at inducer exposures of 30 ms. This difference in temporal dynamics indicates some functional segregation between mechanisms for colour and luminance contrast in the perception of space. (shrink)

Suppose you are presented with three red objects. You are then asked to take a careful look at each possible pair of objects, and to decide whether or not their members look chromatically the same. You carry out the instructions thoroughly, and the following propositions sum up the results of your empirical investigation: <blockquote> i. red object #1 looks the same in colour as red object #2. </blockquote> ii. red object #2 looks the same in colour as red object #3.

My general worry is that Schellenberg’s arguments against naive realism, generalism, and Russellian representationalism do not seem to be successful. Thus her attempt at ruling these views out fails. Her main arguments rely on a shared premise whose plausibility, in the absence of an appropriate theory of particulars, is hard to assess (§2.1). Apart from that, these arguments rely on an under-specified notion of constitution; there seems to be no sense of the term that makes all the premises of her (...) major arguments true without trivializing their conclusions (§2.2). It also seems to me that the challenges that Schellenberg raises for her Russellian opponents, or similar problems, arise for her own view (§3). Finally, Schellenberg believes that an advantage of her view is that it entails the possibility of seeing an object without seeing it as being a certain way. In §4, I argue that it is hard to imagine how one could see without seeing as. (shrink)