Athanassios Raftopoulos

'Epistemological constructivism' holds that vision is mediated by background preconceptions and is theory-laden. Hence, two persons with differing theoretical commitments see the world differently and they could agree on what they see only if they both espoused the same conceptual framework. This, in its turn, undermines the possibility of theory testing and choice on a common theory-neutral empirical basis. In this paper, I claim that the cognitive sciences suggest that a part of vision may be only indirectly penetrated by cognition in a way that does not threaten retrieval of information from a visual scene in a bottom-up way. That blocks the constructivist epistemological thesis. However, since spatial attention, which can be cognitively driven, seems to permeate all stages of visual processes, one is led to conclude that there is no part of vision immune to direct cognitive interference. Against this, I elaborate on the role of spatial attention and argue that it does influence vision in a top-down manner, but it does so only in an indirect way. I then argue that the existence of visual processes that are only indirectly penetrated by cognition undermines the epistemological conclusions of constructivism.

Dartnall claims that visual short-term memory stores nonconceptual content , in the form of compressed images. In this paper I argue against the claim that NCC can be stored in VSTM. I offer four reasons why NCC cannot be stored in visual memory and why only conceptual information can: NCC lasts for a very short time and does not reach either visual short-term memory or visual long-term memory; the content of visual states is stored in memory only if and when object-centered attention modulates visual processing and this modulation signifies the onset of the conceptualization of that content; only categorical high-level information that characterizes conceptual content and not metric and precise iconic information that characterizes NCC can be stored in visual memory for long periods; and if NCC were stored in visual memory then this would allow recognitional judgments pertaining to NCC—one could recognize the precise shade of a color that one had seen before. However NCC does not allow such recognitional judgments

Macpherson (Nous 40(1):82–117, 2006) argues that the square/regular diamond figure threatens representationalism, construed as the theory which holds that the phenomenal character is explained by the nonconceptual content of experience. Her argument is the claim that representationalism is committed to the thesis that differences in the experience of ambiguous figures, the gestalt switch, should be explained by differences in the NCC of perception of these figures. However, with respect to the square/regular diamond and some other ambiguous figure representationalism fails to offer a unified account of how representational content makes them ambiguous. In this paper, I aim, first, to offer a representationalist account of ambiguous figures and, second, to examine and rebut Macpherson’s arguments. My main point is that in each ambiguous figure Macpherson discusses there are differences in representational content that can explain differences in phenomenal character or content. The representational differences are due to the ways the Cartesian frame of reference in which perceptual content is always cast cuts the figure, underlying different properties of the figure with respect to the axes of the Cartesian frame of reference

One of the perennial themes in philosophy is the problem of our access to the world around us; do our perceptual systems bring us into contact with the world as it is or does perception depend upon our individual conceptual frameworks? This volume of new essays examines reference as it relates to perception, action and realism, and the questions which arise if there is no neutral perspective or independent way to know the world. The essays discuss the nature of referring, concentrating on the way perceptual reference links us with the observable world, and go on to examine the implications of theories of perceptual reference for realism and the way in which scientific theories refer and thus connect us with the world. They will be of interest to a wide range of readers in philosophy of science, epistemology, philosophy of psychology, cognitive science and action theory.

The issue of the cognitive impenetrability or penetrability of perception lay dormant for a long period of time. Though philosophers reacted to the relativism implied by the work of Hanson, Kuhn, and Feyerabend, they concentrated their efforts in dealing with the danger of the incommensurability of theories. They tried to show by philosophical and detailed historical analysis that scientists within different paradigms do communicate with each other and put their respective theories to the empirical test. Curiously enough the same philosophers did not seek to examine the very foundation of the relativistic trend, namely the thesis that perception is cognitively penetrable and theory-laden. In the last decade there has been a keen interest in studying the cognition/perception boundary. However, the discussion focused mainly on the grounding of conceptual content on perception and on the embodiment of cognition. The repercussions of these issues for the problem of the cognitive effects on perception were largely ignored. The chapters in this book address directly the issue of the cognitive penetrability of perception. The volume consists of eleven chapters, each one addressing the issue from a different perspective. Eight of the chapters were written by philosophers and cognitive scientists, and three by psychologists and neuropsychologists. These differences notwithstanding, the chapters share many common themes. The role of attention in perception, the contribution of action to perception, the relation between perception and scientific data, the examination of the content of perception and its nature and the detailed examination of the ways background knowledge affects perception, are among these themes. Most chapters combine philosophical analysis with psychological and/or neuropsychological evidence, which shows that there is consensus as to the kind of approaches that are currently deemed necessary for an adequate examination of the problem.

Fodor has argued that observation is theory neutral, since the perceptual systems are modular, that is, they are domain‐specific, encapsulated, mandatory, fast, hard‐wired in the organism, and have a fixed neural architecture. Churchland attacks the theoretical neutrality of observation on the grounds that (a) the abundant top‐down pathways in the brain suggest the cognitive penetration of perception and (b) perceptual learning can change in the wiring of the perceptual systems. In this paper I introduce a distinction between sensation, perception, and observation and I argue that although Churchland is right that observation involves top‐down processes, there is also a substantial amount of information in perception which is theory‐neutral. I argue that perceptual learning does not threaten the cognitive impenetrability of perception, and that the neuropsychological research does not provide evidence in favor of the top‐down character of perception. Finally, I discuss the possibility of an off‐line cognitive penetrability of perception.

Macpherson (2006) argues that the square/regular diamond figure threatens representationalism, which holds that the phenomenal character of experience is either identical, or supervenes on, the nonconceptual content of experience (NCC). Her argument is that representationalism is committed to the thesis that differences in the phenomenal experience of ambiguous figures, the gestalt switch, should be explained by differences in the NCC of perception of these figures. However, with respect to the square/regular diamond figure such differences in NCC do not explain the gestalt switch. I examine Macpherson’s claims and argue that representationalism can account for the experience of ambiguous figures by explaining differences in the phenomenal content of experience by means of differences in the NCC of that same experience. The thrust of my argument is that Macpherson’s account of what happens when subjects, upon viewing a tilted A and an A, report their experience by using the concept-term “A”, mistakes seeph with seedox. If this confusion is cleared, then representationalism can offer a coherent account of the gestalt switch in the diamond/square figure on the basis of the NCC of that experience.

 Constructivism undermines realism by arguing that experience is mediated by concepts, and that there is no direct way to examine those aspects of objects that belong to them independently of our conceptualizations; perception is theory-laden. To defend realism one has to show first that perception relates us directly with the world without any intermediary conceptual framework. The result of this direct link is the nonconceptual content of experience. Second, one has to show that part of the nonconceptual content extracted from the environment correctly represents features of mind independent objects. With regard to the first condition, I have argued elsewhere that a part of visual processing, which I call “perception,” is theory-neutral and nonconceptual. In this paper, facing the second demand, I argue that a part of the nonconceptual content of perception presents properties that are the properties of mind independent objects. I claim first that nonconceptual content is the appropriate level of analysis of the issue of realism since it avoids the main problems besetting various types of analysis of the issue at the level of beliefs about the world. Then I claim that a subset of the nonconceptual content presents features of objects in the environment as they really are

In this paper we address the issue of grounding for experiential concepts. Given that perceptual demonstratives are a basic form of such concepts, we examine ways of fixing the referents of such demonstratives. To avoid ‘encodingism’, that is, relating representations to representations, we postulate that the process of reference fixing must be bottom-up and nonconceptual, so that it can break the circle of conceptual content and touch the world. For that purpose, an appropriate causal relation between representations and the world is needed. We claim that this relation is provided by spatial and object-centered attention that leads to the formation of object files through the function of deictic acts. This entire causal process takes place at a pre-conceptual level, meeting the requirement for a solution to the grounding problem. Finally we claim that our account captures fundamental insights in Putnam’s and Kripke’s work on “new” reference.

It has been a traditional claim that Newtonian inductivism sharply contradicts Cartesian deductivism, and that Newton's rejection of the method of hypothesis is intended as a criticism of the Cartesian scientific methodology. There have been some sharp attacks against the received view that Descartes aimed at the construction of a purely a priori science, but despite this two beliefs still dominate even recent interpretations of Descartes' work. The first is the belief that a significant part of Descartes' natural philosophy was meant to be a priori, and the second is the belief that the Cartesian empirical scientific method was a version of the method of hypothesis. Also, new light has been shed on Newton's famed inductivism and his rejection of the method of hypothesis, a light which shows first, that the traditional inductive interpretation of Newton's method falls significantly short of capturing the richness of this method, and second, that hypotheses play an important role in shaping the conceptual framework in which Newton's work was developed. Despite these recent interpretations, however, an accurate account of Newton's experimental method and an examination of the exact scope and significance of Newton's critique and rejection of the method of hypothesis are still needed. ;The central thesis of this dissertation is that a study of the methodological work and actual scientific practice of Descartes and Newton reveals profound similarities that can be traced back to their employment of the same scientific method of discovery, namely the method of analysis. To that end, I have undertaken a comparative study of the methodological and scientific work of both thinkers. I argue that the official Cartesian method is not the method of hypothesis, and that Descartes did not think any of the parts of his science to be purely a priori. I also argue that the content of Newtonian methodology exceeds that of simple induction, and I try to reconstruct this method as accurately as possible. The conclusion is reached that both Newton and Descartes employed the same scientific method, and that the differences in the fruits delivered by this method are due to the differences between the conceptual frameworks within which Descartes' and Newton's thoughts were developed

In a recent article G. Hatfield claims that Descartes for a certain time thought a purely a priori science to be possible. Hatfield's evidence consists of his reading of the Cartesian method in the Regulae and of a letter to Mersenne, written in May 1632. I argue that Hatfield misinterprets the Cartesian method and Descartes' claim in the letter to Mersenne. I first show that the latter does not argue for an a priori science. Then, I show that the method of the Regulae is not a priori. Finally, I propose a reading of Descartes' letter

I elaborate on Pylyshyn's definition of the cognitive impenetrability (CI) of early vision, and draw on the role of concepts in perceptual processing, which links the problem of the CI or cognitive penetrability (CP) of early vision with the problem of the nonconceptual content (NCC) of perception. I explain, first, the sense in which the content of early vision is CI and I argue that if some content is CI, it is conceptually encapsulated, that is, it is NCC. Then, I examine the definitions of NCC and argue that they lead to the view that the NCC of perception is retrieved in a stage of visual processing that is CI. Thus, the CI of a state and content is a sufficient and necessary condition for the state and its content to be purely NCC, the CI?≡?NCC thesis. Since early vision is CI, the purely NCC of perception is formed in early vision. I defend the CI?≡?NCC thesis by arguing against objections raised against both the sufficient and the necessary part of the thesis.

Toribio argues against my thesis that the cognitive penetrability (CP) of the content of early vision is a necessary and sufficient condition for this content to be nonconceptual content (NCC)–the MET (mutually entailing thesis). Her main point is that MET presupposes a non-standard, causal interpretation of NCC that either trivializes NCC or fails to engage with the contemporary literature on NCC, in which the property of being nonconceptual is not construed in empirical but in constitutive terms. I argue that Toribio's arguments presuppose views of NCC that clash with important themes in the nonconceptualist literature, and that constitutive considerations concerning NCC are inextricably linked with causal considerations since the latter are required to address the concerns that led philosophers to postulate NCC.

The Macpherson :24–62, 2012) argued that the perceptual experience of colors is cognitively penetrable. Macpherson also thinks that perception has nonconceptual content because this would provide a good explanation for several phenomena concerning perceptual experience. To have both, Macpherson must defend the thesis that the CP of perception is compatible with perception having NCC. Since the classical notion of CP of perception does not allow perception to have NCC, Macpherson proposes CP-lite. CP-lite makes room for an experience to have content determined by concepts because the perceptual processes that produce the experience are affected by concepts rendering the experience, CP, while the same type of experience could have been had without any conceptual influences, in which case it would be CI. Macpherson then proceeds to show that CP-lite is compatible with some of the definitions of NCC. To do so, she argues that even when an experience is CP owing to the fact that it is produced by means of the mechanism posited by CP-lite, that is, through the interaction between bottom–up pure perception and top–down perceptual imagery, its content is NCC because it has the basic properties that characterize NCC. Based on this, Macpherson proceeds to criticize and undermine the definitions of NCC that are incompatible with CP-lite. In this paper, I argue that the possibility of CP-lite rests on the erroneous assumption that a state with conceptual content and a state with NCC can have the same phenomenology or content, and that the compatibility of CP-lite with NCC presupposes a view of NCC that does not conform to the usual construal of NCC.

We discuss at some length evidence from the cognitive science suggesting that the representations of objects based on spatiotemporal information and featural information retrieved bottomup from a visual scene precede representations of objects that include conceptual information. We argue that a distinction can be drawn between representations with conceptual and nonconceptual content. The distinction is based on perceptual mechanisms that retrieve information in conceptually unmediated ways. The representational contents of the states induced by these mechanisms that are available to a type of awareness called phenomenal awareness constitute the phenomenal content of experience. The phenomenal content of perception contains the existence of objects as separate things that persist in time and time, spatiotemporal information, and information regarding relative spatial relations, motion, surface properties, shape, size, orientation, color, and their functional properties.

In this paper I argue for the cognitive impenetrability of perception by undermining the argument from reentrant pathways. To do that I will adduce psychological and neuropsychological evidence showing that (a) early vision processing is not affected by our knowledge about specific objects and events, and (b) that the role of the descending pathways is to enable the early-vision processing modules to participate in higher-level visual or cognitive functions. My thesis is that a part of observation, which I will call perception, is bottom-up and theory neutral. As such, perception could play the role of common ground on which a naturalized epistemology can be built and relativism avoided

It has been a traditional claim that Descartes sought to construct a deductive scientific system in which everything could be deduced from a priori truths. I shall call this thesis strong a priorism. In view of the overwhelming amount of evidence that Descartes thought experience to be a necessary part of his method, the traditional interpretation has undergone several transformations. One interpretation resulting from this transformation holds that Descartes sought to prove the first principles of natural philosophy in an a priori manner. I will call this interpretation weak a priorismk.My task in this paper is to show that the thesis of weak a priorismk is false. With a view to proving this, I will show that one of the very general principles of Cartesian natural philosophy, namely, the claim that the essence of matter is extension, could not have been, and was not meant to be, established in a purely a priorik way.