Athanassios Raftopoulos

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.

Studies on the syndrome called ‘unilateral visual or spatial neglect’ have been used by philosophers in discussions concerning perceptual phenomenology. Nanay , based on spatial neglects studies, argued that the property of being suitable for action is part of the perceptual phenomenology of neglect patients. In this paper, I argue that the studies on visual neglect conducted thus far do not support Nanay’s thesis that when patients succeed in detecting the neglected object, it’s action properties are part of their perceptual phenomenology; instead, the support the view that the patients consciously see low-level properties such as color and shape. In the first section, I discuss unilateral neglect and extinction. In the second section, I analyze Nanay’s argument. In the third section, I explain why Nanay’s thesis does not follow from the studies on visual neglect. Nanay argues that when neglect patients are cued with an action-property of an object and succeed in perceiving the object in the contralesional side they are phenomenally aware of an action-property of it but they are not phenomenally aware of its low-level properties. Since the patients detect the object, they must be phenomenally aware of some of its properties. Failing to see the low-level properties, the patients should be phenomenally aware is the action-property. Against this, I argue that research on spatial neglect shows that the patients come to see the low-level properties. I also explain why my discussion also supports the more general claim that the studies on neglect and extinction conducted thus far do not establish that the action-properties are part of the patients’ phenomenology. Finally, in section four, I examine a possible objection against my account. My arguments do not entail that the action properties are not part of perceptual phenomenology; only that the neglect studies do not establish this

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.