In the philosophy of mind, revelation is the claim that the nature of qualia is revealed in phenomenal experience. In the literature, revelation is often thought of as intuitive but in tension with physicalism. While mentions of revelation are frequent, there is room for further discussion of how precisely to formulate the thesis of revelation and what it exactly amounts to. Drawing on the work of David Lewis, this paper provides a detailed discussion on how the thesis of revelation, as (...) well as its incompatibility with physicalism, is to be understood. (shrink)

In this thesis, I will defend a new kind of compatibilist account of free action, indirect conscious control compatibilism (or indirect compatibilism for short), and argue that some of our actions are free according to it. My argument has three components, and involves the development of a brand new tool for experimental philosophy, and the use of cognitive neuroscience. The first component of the argument shows that compatibilism (of some kind) is a conceptual truth. Contrary to the current orthodoxy in (...) the free will literature, which is that our concept of free will is an incompatibilist concept - a concept according to which we have free will only if determinism is false - I will show that our concept of free will is in fact a compatibilist concept - a concept according to which we can have free will even if determinism is true - and I do so using a new experimental philosophy methodology inspired by two-dimensional semantics. -/- Of course, even if our concept of free will is a compatibilist concept, this does not mean that there are any free actions in the world: the current empirical evidence from the brain sciences appears to show that there might be no, or very few, free actions in the world, even on many compatibilist understandings of what it would take for there to be free will. The second component of the argument addresses this concern by extending our understanding of compatibilism. Agents act freely either when their actions are caused by compatibilistically acceptable psychological processes, or are indirectly caused by those same processes. Hence the name of my account: indirect compatibilism. -/- The final component of the argument defends my new account against some interesting objections and provides evidence from cognitive neuroscience that some of our actions count as free by the lights of indirect compatibilism. (shrink)

We propose a new approach to the study of introspection. Instead of asking what form introspection actually takes in humans or other animals, we ask what forms it could take, in natural or artificial minds. What are the dimensions along which forms of introspection could vary? This is a relatively unexplored question, but it is one that has the potential to open new avenues of study and reveal new connections between existing ones. It may, for example, focus attention on possible (...) forms of introspection radically different from the human one and help to integrate competing theories of human introspection in a non-adversarial manner. We introduce and motivate the project, provide a preliminary mapping of the space of possible forms of introspection, and sketch a programme for interdisciplinary research on the topic. (shrink)

Why do we tend to think that phenomenal consciousness poses a hard problem? The answer seems to lie in part in the fact that we have the impression that phenomenal experiences are presented to us in a particularly immediate and revelatory way: we have a sense of acquaintance with our experiences. Recent views have offered resources to explain such persisting impression, by hypothesizing that the very design of our cognitive systems inevitably leads us to hold beliefs about our own experiences (...) with certainty. I argue against this kind of “designed certainty” views. First, I claim that it is doubtful that we really hold beliefs about our own experiences with certainty—in any sense of certainty that would make our phenomenal beliefs special. Second, I claim that, even if it were the case that we hold beliefs about experiences with certainty, this would fall short of explaining our sense of acquaintance. (shrink)

Kripke's argument against the identity theory in the philosophy of mind runs as follows. Suppose some psychophysical identity statement S is true. Then S would seem to be contingent at least in the sense that S seems possibly false. And given that seeming contingency entails genuine contingency when it comes to such statements S is contingent. But S is necessary if true. So S is false. This entry considers responses to each of the three premises. It turns out that each (...) response does not fully withstand scrutiny, and so Kripke's conclusion is hard to resist. Section 1 lays out Kripke's argument, and Sections 2 to 4 then discuss responses to each of the three premises respectively. (shrink)

‘Space does not exist fundamentally: it emerges from a more fundamental non-spatial structure.’ This intriguing claim appears in various research programs in contemporary physics. Philosophers of physics tend to believe that this claim entails either that spacetime does not exist, or that it is derivatively real. In this article, I introduce and defend a third metaphysical interpretation of the claim: reductionism about space. I argue that, as a result, there is no need to subscribe to fundamentality, layers of reality and (...) emergence in order to analyse the constitution of space by non-spatial entities. It follows that space constitution, if borne out, does not provide empirical evidence in favour of a stratified, Aristotelian in spirit, metaphysics. The view will be described in relation to two particular research programs in contemporary physics: wave function realism and loop quantum gravity. (shrink)

How could perceptual experiences reveal matters of essentiality? Answering this question is crucial for vindicating a thesis about the epistemic import of experience, commonly known as Revelation. The thesis comes in a weak and a strong version. Only on the strong one could it make up an authoritative piece of common sense. But this version also seems to demand too much of our experiences, namely that they can reveal essentiality. However, the impression that our experiences are not suited for this (...) turns out to be due to a non-mandatory assumption about how the revelation of essentiality would work. (shrink)

In this paper, we describe four broad ‘meta-methods’ employed in scientific and philosophical research of qualia. These are the theory-centred metamethod, the property-centred meta-method, the argument-centred meta-method, and the event-centred meta-method. Broadly speaking, the theory-centred meta-method is interested in the role of qualia as some theoretical entities picked out by our folk psychological theories; the property-centred meta-method is interested in some metaphysical properties of qualia that we immediately observe through introspection ; the argument-centred meta-method is interested in the role of (...) qualia in some arguments for non-physicalism; the event-centred metamethod is interested in the role of qualia as some natural events whose nature is hidden and must be uncovered empirically. We will argue that the event-centred metamethod is the most promising route to a comprehensive scientific conception of qualia because of the flexibility of ontological and methodological assumptions it can provide. We also reveal the hidden influences of the different meta-methods and in doing so show why consideration of meta-methods has value for the study of consciousness. (shrink)

According to structuralism, all natural properties are individuated by their roles in causal/nomological structures. According to quidditism, at least some natural properties are individuated in some other way. Because these theses deal with the identities of natural properties, this distinction cuts to the core of a serious metaphysical dispute: Are the intrinsic natures of all natural properties essentially causal/nomological in character? I'll argue that the answer is ‘no’, or at least that this answer is more plausible than many critics of (...) quidditism have recognized. In section 1, I distinguish between two versions of quidditism. Bare quidditism holds that worlds with distinct properties and isomorphic structures must be qualitatively identical in the following sense: inhabiting one world would be indistinguishable from inhabiting the other. In contrast, qualitative quidditism allows such worlds to have qualitative differences. In section 2, I discuss an epistemological position that allows us to bett... (shrink)

This paper expands on the discussion in the first section of 'Beyond phenomenal naivete'. Let Phenomenal Naivete be understood as the doctrine that some phenomenal characters of veridical experiences are factive properties concerning the external world. Here I present in detail a phenomenological case for Phenomenal Naivete and an argument from hallucination against it. I believe that these arguments show the concept of phenomenal character to be defective, overdetermined by its metaphysical and epistemological commitments together with the world. This does (...) not establish a gappish eliminativism, but a gluttish pluralism, on which there are many imperfect deservers of the name 'phenomenal character'. Different projects in the philosophy of mind -- phenomenology, philosophy of conscious, metaphysics and epistemology of perception -- are concerned with different deservers of the name. (shrink)

Jackson argues that conceptual analysis plays a modest, albeit crucial, role in ‘serious metaphysics’: roughly, the project of demystifying phenomena we take to be mysterious by locating them in the natural world. This defence of conceptual analysis is associated with ‘the Canberra Plan’, a philosophical methodology that has its roots in the works of both Lewis :427–446, 1970, Australas J Philos 50:249–258, 1972) and Jackson. There is, however, a distinction to be drawn between conceptual analysis, as it is typically employed (...) in the Canberra plan, and a version of it defended by Jackson himself. In this paper, I elucidate this distinction, and employ examples from the history of science to argue the use of the former, but not the latter, incurs certain problems of conceptual change. Moreover, I also argue neither can be used to undertake serious metaphysics—the former because of the aforementioned problems, and the latter due to the machinery it employs to solve them. (shrink)

‘Egalitarian' views of consciousness treat my stream of consciousness and yours as on a par ontologically. A range of worries about Chalmers's philosophical system are traced to a background presupposition of egalitarianism: Chalmers is apparently committed to ‘soul pellets'; the ‘phenomenal properties' at the core of the system are obscure; a ‘vertiginous question' about my identity is raised but not adequately answered; the theory of phenomenal concepts conflicts with the ‘transparency of experience'; the epistemology of other minds verges very close (...) to a priori physicalism; the system predicts that dualism is alluring, when it is not. (shrink)

‘What it is like’ talk (‘WIL-talk’) — the use of phrases such as ‘what it is like’ — is ubiquitous in discussions of phenomenal consciousness. It is used to define, make claims about, and to offer arguments concerning consciousness. But what this talk means is unclear, as is how it means what it does: how, by putting these words in this order, we communicate something about consciousness. Without a good account of WIL-talk, we cannot be sure this talk sheds light, (...) rather than casts shadows, on our investigations of consciousness. The popular technical account of WIL-talk (see e.g. Lewis, 1995, and Kim, 1998) holds that WIL-talk involves technical terms — terms which look like everyday words but have a distinct meaning — introduced by philosophers. I argue that this account is incorrect by showing that the alleged technical terms were not introduced by philosophers, and that these terms do not have a technical meaning. (shrink)

What is the connection between having a phenomenal property and knowing that one has that property? A traditional view on the matter takes the connection to be quite intimate. Whenever one has a phenomenal property, one knows that one does. Recently most authors have denied this traditional view. The goal of this paper is to defend the traditional view. In fact, I will defend something much stronger: I will argue that what it is for a property to be phenomenal is (...) for it to be a property one must know oneself to have when on has it. As we will see, this theory has a number of surprising and welcome upshots, suggesting that the traditional view has been unjustly maligned. (shrink)

David Lewis argues for Ramseyan humility, the thesis that we can’t identify the fundamental properties that occupy the nomological roles at our world. Lewis, however, remarks that there is a potential exception to this, which involves assuming two views concerning qualia panphenomenalism : all instantiated fundamental properties are qualia and the identification thesis : we can know the identities of our qualia simply by being acquainted with them. This paper aims to provide an exposition, as well as an assessment, of (...) this response to the humility thesis. (shrink)

It is often held that to have a conscious experience presupposes having some form of implicit self-awareness. The most dominant phenomenological view usually claims that we essentially perceive experiences as our own. This is the so called “mineness” character, or dimension of experience. According to this view, mineness is not only essential to conscious experience, it also grounds the idea that pre-reflective self-awareness constitutes a minimal self. In this paper, we show that there are reasons to doubt this constituting role (...) of mineness. We argue that there are alternative possibilities and that the necessity for an adequate theory of the self within psychopathology gives us good reasons to believe that we need a thicker notion of the pre-reflective self. To this end, we develop such a notion: the Pre-Reflective Situational Self. To do so, we will first show how alternative conceptions of pre-reflective self-awareness point to philosophical problems with the standard phenomenological view. We claim that this is mainly due to fact that within the phenomenological account the mineness aspect is implicitly playing several roles. Consequently, we argue that a thin interpretation of pre-reflective self-awareness—based on a thin notion of mineness—cannot do its needed job within, at least within psychopathology. This leads us to believe that a thicker conception of pre-reflective self is needed. We, therefore, develop the notion of the pre-reflective situational self by analyzing the dynamical nature of the relation between self-awareness and the world, specifically through our interactive inhabitation of the social world. (shrink)

This article is about the distinction between justification and excuse, a distinction which, while familiar, remains controversial. My discussion focuses on three questions. First, what is the distinction? Second, why is it important? And third, what are some areas of inquiry in which the distinction might be philosophically fruitful? I suggest that the distinction has practical and theoretical consequences, and is therefore worth taking seriously; I highlight two philosophical issues in which the distinction might play a useful role; but I (...) express skepticism about the prospects for drawing a firm distinction between justification and excuse. (shrink)

We defend Laurence Nemirow’s and David Lewis’s Ability Hypothesis against Paul Raymont’s criticisms in defense of Jackson’s Knowledge Argument. According to the Ability Hypothesis, what Mary lacked when she was in her black-and-white room was a set of abilities; she did not know how to recognize or imagine certain types of experience. Her subsequent discovery of what it is like to experience color amounts to no more than her acquiring these abilities. Appealing to the Molyneux test, Raymont has argued that (...) knowledge of what an experience is like cannot be equated with the possession of any set of abilities, since one can be in possession of a recognitional ability concerning a certain type of experience without knowing what that experience is like. We argue that the intermodal recognitional ability in the Molyneux test and similar ones depends on previous experience and thus makes an implicit appeal to knowledge of what it is like. (shrink)

It is usually agreed that the Revelation Thesis about experience – the idea that the knowledge we gain by having an experience somehow “reveals” the essence, or nature, of this experience – only requires that we know the essence of the experience, not that we know, of this essence, that it is the essence of the experience. I contest this agreement. In the light of what I call the “Essentiality of Essence Principle”– the principle that whatever is in the essence (...) of something is also essentially so – I argue that the Revelation Thesis does require that we know, of the essence of an experience, that it is the essence of the experience, and draw some conclusions about the plausibility of that thesis. (shrink)

This chapter reviews four elements of David Lewis's account of materialism and experience. These elements include: materialism for which Lewis gave a distinctive and well‐known characterization; an account of what experience is; an account of the source of the tension between experience and materialism; and a strategy for resolving the tension. Lewis did not just give a distinctive and well‐known characterization of materialism, he gave two: one in terms of fundamental properties, and one in terms of supervenience. The chapter considers (...) two recent objections to that account. The first argues that knowledge‐how is a certain kind of knowledge‐that and in consequence Lewis's well‐known “ability hypothesis” fails. The second argues that if Lewis's contextualist approach to epistemology is correct, his rejection of the identification thesis is impossible. The author suggests that Lewis has the resources to answer both objections, but he ends by stating the real problems for Lewis's lie. (shrink)

What is the connection between being in a conscious mental state and believing that you yourself are currently in that state? On the one hand, it is natural to think that this connection is, or involves, a necessary connection of some sort. On the other hand, it is hard to know what the nature of this necessary connection is. For there are plausible arguments according to which this connection is not metaphysically necessary, not rationally necessary, and not merely naturally necessary. (...) If these arguments are correct, and if these options are exhaustive, while there is a necessary connection between a conscious state and the belief that you are in it, there is apparently no necessary connection it could be! This paper sets out this problem—the necessary connection problem, I will call it—and defends and explores a novel proposal about how to solve it. (shrink)

David Lewis's position, often called analytic functionalism, was inspired by Ryle's analytic behaviorism, which took psychological predicates to express complex sets of behavioral dispositions. In this chapter, the author reviews some tenets of Lewis's philosophy of mind and begins with some comments on the methodology Lewis employed in his analysis of psychological terms, which has become standard in functionalist accounts across philosophy. Then, he discusses the difference between what are often called “realizer functionalism” and “role functionalism,” and argues that Lewis (...) made the wrong choice. In Lewis's argument for the identity theory, the identity of mental states with biological states follows logically from folk‐psychological definitions and broadly physical facts. A central part of folk psychology concerns the interaction of beliefs, desires, and choices. The chapter presents Lewis's often misunderstood account of intentionality. It also presents few pessimistic remarks on the prospect of analyzing phenomenal truths in terms of functional role. (shrink)

I defend Frank Jackson's knowledge argument against physicalism in the philosophy of mind from a criticism that has been advanced by Laurence Nemirow and David Lewis. According to their criticism, what Mary lacked when she was in her black and white room was a set of abilities; she did not know how to recognize or imagine certain types of experience from a first-person perspective. Her subsequent discovery of what it is like to experience redness amounts to no more than her (...) acquisition of these abilities. The physicalist can admit this, since it does not commit one to the view that there are any facts of which Mary was ignorant . I argue against this view, on the grounds that the knowledge of what an experience is like cannot be equated with the possession of any set of abilities. (shrink)

Dualists say plausible things about our mental concepts: there is a way of thinking of pain, in terms of how it feels, which is independent of causal role. Physicalists make attractive ontological claims: the world is wholly physical. The attraction of a posteriori physicalism is that it has seemed to do both: to agree with the dualist about our mental concepts, whilst retaining a physicalist ontology. In this paper I argue that, in fact, a posteriori physicalism departs from the dualist's (...) intuitive picture of our phenomenal concepts in just as radical a manner as more traditional forms of physicalism. Whereas the physicalism of David Lewis and David Armstrong is counterintuitive in holding that our only way of thinking about pain is in terms of its causal role, the physicalism of David Papineau and Brian Loar departs from common sense in holding that our phenomenal concept of pain is opaque: thinking of pain in terms of how it feels reveals nothing of what it is for something to feel pain. The arguments of David Chalmers and Frank Jackson against a posteriori physicalism involve general claims about all concepts. In contrast, my argument makes a claim only about phenomenal concepts: phenomenal concepts are not opaque. (shrink)

Although they may differ on the reason why, many philosophers hold that it is a priori that an object is red if and only if it is such as to look red to normal observers in normal conditions.

This is a bibliography of books and articles on consciousness in philosophy, cognitive science, and neuroscience over the last 30 years. There are three main sections, devoted to monographs, edited collections of papers, and articles. The first two of these sections are each divided into three subsections containing books in each of the main areas of research. The third section is divided into 12 subsections, with 10 subject headings for philosophical articles along with two additional subsections for articles in cognitive (...) science and neuroscience. Of course the division is somewhat arbitrary, but I hope that it makes the bibliography easier to use. This bibliography has first been compiled by Thomas Metzinger and David Chalmers to appear in print in two philosophical anthologies on conscious experience . From 1995 onwards it has been continuously updated by Thomas Metzinger, and now is freely available as a PDF-, RTF-, or HTML-file. This bibliography mainly attempts to cover the Anglo-Saxon and German debates, in a non-annotated, fully formatted way that makes it easy to "cut and paste" from the original file. To a certain degree this bibliography also contains items in other languages than English and German - all submissions in other languages are welcome. Last update of current version: July 13th, 2001. (shrink)

This paper aims to uncover where the disagreement between illusionism and anti-illusionism about phenomenal consciousness lies fundamentally. While illusionists claim that phenomenal consciousness does not exist, many philosophers of mind regard illusionism as ridiculous, stating that the existence of phenomenal consciousness cannot be reasonably doubted. The question is, why does such a radical disagreement occur? To address this question, I list various characterisations of the term “phenomenal consciousness”: (1) the what-it-is-like locution, (2) inner ostension, (3) thought experiments such as philosophical (...) zombies, inverted qualia and Mary’s room, (4) scientific knowledge about secondary properties, (5) theoretical properties such as being ineffable and being intrinsic, and (6) appearance/reality collapse. Then I examine whether each characterization provides (i) a dubitable sense of phenomenal consciousness in which the existence of phenomenal consciousness can be reasonably doubted, (ii) an indubitable sense in which its existence cannot be reasonably doubted, or (iii) a gray sense in which it is controversial whether its existence can be reasonably doubted. By doing so, I show that there is no single sense of phenomenal consciousness in which illusionists and anti-illusionists disagree whether the existence of phenomenal consciousness can be reasonably doubted. I conclude that the disagreement between illusionists and anti-illusionists is fundamentally terminological: while illusionists adopt a dubitable sense of phenomenal consciousness, anti-illusionists adopt an indubitable sense of phenomenal consciousness. Because of the extreme vagueness and ambiguity of the term “phenomenal consciousness”, illusionists and anti-illusionists fail to see that they talk about different senses of phenomenal consciousness. (shrink)

In De Trinitate 10, Augustine offers an argument that seemingly proceeds from certain premises about self-knowledge to the conclusion that the mind is incorporeal. Although the argument has sometimes been compared to later Cartesian arguments, it has received relatively little philosophical attention. In this paper, I offer a detailed analysis and original interpretation of Augustine's argument and argue that it is not vulnerable to some of the main objections which have been raised against it. I go on to argue that (...) while an important part of Augustine's argument does face several hitherto neglected objections, Augustine's ultimate case for the incorporeality of the mind is somewhat different and more successful than one might initially think. (shrink)

Let's be externalists about perceptual consciousness and think the form of veridical perceptual consciousness includes /seeing this or that mind-independent particular and its colors/. Let's also take internalism seriously, granting that spectral inversion and hallucination can be "phenomenally" the same as normal seeing. Then perceptual consciousness and phenomenality are different, and so we need to say how they are related. It's complicated!<br><br>Phenomenal sameness is (against all odds) /reflective indiscriminability/. I build a "displaced perception" account of reflection on which indiscriminability stems (...) from shared "qualia". Qualia are compatible with direct realism: while they generate an explanatory gap (and colors do not), so does /seeing/; qualia are excluded from perceptual consciousness by its "transparency"; instead, qualia are aspects of thought about the perceived environment. <br><br>The asymmetry between my treatments of color and seeing is grounded in the asymmetry between ignorance and error: while inversion shows that normal subjects are ignorant of the natures of the colors, hallucination shows not that perceivers are ignorant of the nature of seeing but that hallucinators are prone to error about their condition. Past literature has treated inversion and hallucination as on a par: externalists see error in both cases, while internalists see mutual ignorance. My account is so complicated because plausible results require mixing it up. (shrink)

I argue on linguistic grounds that when Mary comes to know what it's like to see a red thing, she comes to know a certain inexpressible truth about the character of her own experience. This affords a "no concept" reply to the knowledge argument. The reason the Knowledge Argument has proven so intractable may be that we believe that an inexpressible concept and an expressible concept cannot have the same referent.

(2014). A Priori Conditionals and the Conceivability of Zombies. Philosophical Papers: Vol. 43, No. 2, pp. 227-253.

In recent literature on the metaphysics of consciousness, and in particular on the prospects of physicalism, there are two interesting strands of discussion. One strand concerns the so-called ‘thesis of revelation’, the claim that the essences of phenomenal properties are revealed in experience. The other strand concerns the intuition of dualism, the intuition that consciousness is nonphysical. With a particular focus on the former, this paper advances two main arguments. First, it argues that the thesis of revelation is intuitive; it (...) is part of our ordinary, implicit conception of experience. Second, it brings the two strands of discussion together and puts forward a rational explanation of the intuition of dualism in terms of the intuitiveness of the thesis of revelation. (shrink)

The Humility Thesis is a persistent thesis in contemporary metaphysics. It is known by a variety of names, including, but not limited to, Humility, Intrinsic Humility, Kantian Humility, Kantian Physicalism, Intrinsic Ignorance, Categorical Ignorance, Irremediable Ignorance, and Noumenalism. According to the thesis, we human beings, and any knowers that share our general ways of knowing, are irremediably ignorant of a certain class of properties that are intrinsic to material entities … Continue reading Humility Regarding Intrinsic Properties →.

Much of contemporary philosophy of mind is marked by a dissatisfaction with the two main positions in the field, standard materialism and standard dualism, and hence with the search for alternatives. My concern in this paper is with two such alternatives. The first, which I will call non-standard materialism, is a position I have defended in a number of places, and which may take various forms. The second, panpsychism, has been defended and explored by a number of recent writers. My (...) main goals are: (a) to explain the differences between these positions; and (b) to suggest that non-standard materialism is more plausible than panpsychism. (shrink)

This commentary focuses on explaining the intuition of revelation, an issue that Chalmers (2018) raises in his paper. I first sketch how the truth of revelation provides an explanation for the intuition of revelation, and then assess a physicalist proposal to explain the intuition that appeals to Derk Pereboom’s (2011, 2016, 2019) qualitative inaccuracy hypothesis.

David Lewis David Lewis is an American philosopher and one of the last generalists, in the sense that he was one of the last philosophers who contributed to the great majority of sub-fields of the discipline. He made central contributions in metaphysics, the philosophy of language, the philosophy of mind, and probabilistic and practical … Continue reading David Lewis →.

The thesis is intended to contribute to the growing understanding of the indispensable role played by phenomenal consciousness in human cognition, and specifically in making our concepts of the external world available. The focus falls on so called observational concepts, a type of rudimentary, perceptually-based objective concepts in our repertoire — picking out manifest properties such as colors and shapes. A theory of such concepts gets provided, and, consequently, the exact role that perceptual consciousness plays in making concepts of this (...) sort available gets settled. In the first half of the thesis, observational concepts get construed as a special type of recognitional concepts. On an analogy with perceptual demonstratives, having such concepts would involve having non-trivial knowledge of their reference. The experiential basis of such concepts would, among other things, provide for such constitutive knowledge. The theoretical background relevant to the hypothesis gets provided in the first chapter. A defence of the hypothesis follows in the second. In the second half of the thesis, care is taken to distinguish among two ways in which the constitutive knowledge of the reference of an observational concept could be fleshed out. In the third chapter, perceptual experience is shown to provide the basis both for knowledge of observational properties by acquaintance, and for knowledge of the essence of such properties — provided that knowledge of essence gets construed in the right, modest way. It might be natural to take knowledge by acquaintance to be the sort relevant to observational concept possession, especially given that in the case of perceptual demonstratives this is the role likely played by experience. However, this initial impression proves to be mistaken. The constitutive knowledge of the referent of an observational concept turns out to consist in the capacity to determine a priori the essence of the respective property. To show this, an argument gets provided in the penultimate fourth chapter, based on the key role played by experiences of instances of observational properties in optimal viewing conditions in enabling the possession of the respective observational concept. (shrink)