Athanassios Raftopoulos

In this paper, I claim that since there is a cognitively impenetrable stage of visual perception, namely early vision, and cognitive penetrability and theory-ladenness are coextensive, the CI of early vision entails that early vision content is theory neutral. This theory-neutral part undermines relativism. In this paper, I consider two objections against the thesis. The one adduces evidence from cases of rapid perceptual learning to undermine my thesis that early vision is CI. The other emphasizes that the early perceptual system, in order to solve various underdetermination problems, relies on certain principles, which may be taken to constitute a sort of a theory about the world that affect early vision, rendering it theory-laden. Both objections purport to show that early vision is CP and theory-laden. Against this thesis, I argue that the evidence on which the two objections are based does not show that early vision is CP and is fully compatible with the view that early vision is CI.

In this paper I discuss Newton's first optical paper. My aim is to examine the type of argument which Newton uses in order to convince his readers of the truth of his theory of colors. My claim is that this argument is an induction by elimination, and that the Newtonian method of justification is a kind of “generative justification”, a term due to T. Nickles. To achieve my aim I analyze in some detail the arguments in Newton's first optical paper, relating the paper with Newton's other writings in optics, and especially his early correspondence in defence of his theory of colors.

This paper aims to provide an explication of the meaning of ‘analysis’ and ‘synthesis’ in Descartes’ writings. In the first part I claim that Descartes’ method is entirely captured by the term ‘analysis’, and that it is a method of theory elaboration that fuses the modern methods of discovery and confirmation in one enterprise. I discuss Descartes’ methodological writings, assess their continuity and coherence, and I address the major shortcoming of previous interpretations of Cartesian methodology. I also discuss the Cartesian method in the context of other conceptions of scientific method of that era and argue that Descartes’ method significantly transforms these conceptions. In the second part I argue that mathematical and natural-philosophical writings exhibit this kind of analysis. To that effect I examine in Descartes’ writings on the method as used in mathematics, and Descartes’ account of the discovery of the nature of the rainbow in the Meteors. Finally, I briefly assess Descartes’ claim regarding the universality of his method.Author Keywords: Cartesian method; Theory elaboration; Analysis; Synthesis; Simple natures; Rainbow.

I examine John Campbell’s claim that the determination of the reference of a perceptual demonstrative requires conscious visual object-based selective attention. I argue that although Campbell’s claim to the effect that, first, a complex binding parameter is needed to establish the referent of a perceptual demonstrative, and, second, that this referent is determined independently of, and before, the application of sortals is correct, this binding parameter does not require object-based attention for its construction. If object-based attention were indeed required then the determination of the referent would necessarily involve the application of sortal concepts, since object-based attention initiates top-down cognitive effects on visual processing. I also examine Mohan Matthen’s claim that reference to objects is established only through the visual processing in the dorsal visual stream and argue that although it is true that processing in the dorsal stream can determine reference, a thesis that goes against Campbell’s view that the determination of the referent requires conscious attention, processing along the ventral visual stream can also establish the reference of perceptual demonstratives. It also claim that Matthen’s account of dorsal processing underestimates the kind of information processed along the dorsal stream and this has some implications regarding perceptual demonstratives reference fixing.

'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.