An overview of higher-order representational theories of consciousness. Representational theories of consciousness attempt to reduce consciousness to “mental representations” rather than directly to neural or other physical states. This approach has been fairly popular over the past few decades. Examples include first-order representationalism (FOR) which attempts to explain conscious experience primarily in terms of world-directed (or first-order) intentional states (Tye 2005) as well as several versions of higher-order representationalism (HOR) which holds that what makes (...) a mental state M conscious is that it is the object of some kind of higher-order mental state directed at M. The primary focus of this entry is on HOR and especially higher-order thought (HOT) theory. The key question that should be answered by any theory of consciousness is: What makes a mental state a conscious mental state? Section 1 introduces the overall representationalist approach to consciousness and briefly discuss Tye’s FOR. Section 2 presents three major versions of HOR: higher-order thought theory, dispositional higher-order thought theory, and higher-order perception theory. In section 3, a number of common and important objections and replies are presented. Section 4 briefly outlines a close connection between HOT theory and conceptualism, that is, the claim that the representational content of a perceptual experience is entirely determined by the conceptual capacities the perceiver brings to bear in her experience. Section 5 examines several hybrid higher-order and “self-representational” theories of consciousness which all hold that conscious states are self-directed in some way. Section 6 addresses the potentially damaging claim that HOT theory requires neural activity in the prefrontal cortex (PFC) in order for one to have conscious states. (shrink)

Ambitious higher-order theories of consciousness aim to account for conscious states when these are understood in terms of what-it-is-like-ness. This paper considers two arguments concerning this aim, and concludes that ambitious theories fail. The misrepresentation argument against HO theories aims to show that the possibility of radical misrepresentation—there being a HO state about a state the subject is not in—leads to a contradiction. In contrast, the awareness argument aims to bolster HO theories by showing that subjects are aware (...) of all their conscious states. Both arguments hinge on how we understand two related notions which are ubiquitous in discussions of consciousness: those of what-it-is-like-ness and there being something it is like for a subject to be in a mental state. This paper examines how HO theorists must understand the two crucial notions if they are to reject the misrepresentation argument but assert the awareness argument. It shows that HO theorists can and do adopt an understanding—the HO reading—which seems to give them what they want. But adopting the HO reading changes the two arguments. On this reading, the awareness argument tells us nothing about those states there is something it is like to be in, and so offers no support to ambitious HO theories. And to respond to the misrepresentation understood according to the HO reading is to simply ignore the argument presented, and so to give no response at all. As things stand, we should deny that HO theories can account for what-it-is-like-ness. (shrink)

Emotional states of consciousness, or what are typically called emotional feelings, are traditionally viewed as being innately programed in subcortical areas of the brain, and are often treated as different from cognitive states of consciousness, such as those related to the perception of external stimuli. We argue that conscious experiences, regardless of their content, arise from one system in the brain. On this view, what differs in emotional and non-emotional states is the kind of inputs that are processed by a (...) general cortical network of cognition, a network essential for conscious experiences. Although subcortical circuits are not directly responsible for conscious feelings, they provide non-conscious inputs that coalesce with other kinds of neural signals in the cognitive assembly of conscious emotional experiences. In building the case for this proposal, we defend a modified version of what is known as the higher-order theory of consciousness. (shrink)

Higher‐order theories purport to account for the conscious character of such states in terms of higher‐order representations. This chapter focuses on three classes of higher‐order theory of phenomenal consciousness, including inner‐sense theory, actualist higher‐order thought theory, and dispositionalist higher‐order thought theory. All three of these higher‐order theories purport to offer reductive explanations of phenomenal consciousness. Inner‐sense theory has important positive virtues, but faces problems; (...) whereas actualist higher‐order thought theory avoids those problems, but at the cost of losing the positive virtues. Actualist higher‐order thought theory has the advantage that no special organs or mechanisms need to be postulated. Dispositionalist higher‐order thought theory claims to split the difference, providing an account that has all of the advantages of inner‐sense theory with none of the flaws. The success of dispositionalist higher‐order thought theory is premised upon the existence of dual analog contents. (shrink)

Higher-order theories of consciousness come in many varieties, but all adopt the 'transitivity principle' as a central, explanatory premise. The transitivity principle states that a mental state of a subject is conscious if and only if the subject is aware of it. This higher-order awareness is realized in different ways in different forms of higher-order theory. I argue that empirical studies of metacognition have falsified the transitivity principle by showing that there can be (...) awareness of a mental state without that state's becoming conscious. I present two such studies in detail and argue that the measures they employ cannot be interpreted in a way that would make the results compatible with higher-order theory. Since all versions of the theory rely on the transitivity principle, this entails that all forms of higher-order theory are false. (shrink)

ABSTRACTAmbitious Higher-order theories of consciousness – Higher-order theories that purport to give an account of phenomenal consciousness – face a well-known objection from the possibility of ra...

It is widely held that consciousness is partially constituted by a “pre-reflective” self-consciousness. Further, it’s argued that the presence of pre-reflective self-consciousness poses a problem for “higher-order” theories of consciousness. Higher-order theories invoke reflective representation and so do not appear to have the resources to explain pre-reflective self-consciousness. This criticism is rooted in the Heidelberg School’s deep reflection on the nature of self-consciousness, and accordingly, I will label this challenge the “Heidelberg problem.” In this chapter, I (...) will offer a higher-order answer to the Heidelberg problem. Instead of attacking the problem head-on, I’ll argue that the view can explain why there appears to be a Heidelberg problem, even if consciousness is ultimately realized by higher-order representation. But I’ll also argue that the theory has indexical resources to more directly counter the Heidelberg problem. Either way, I hope to show that the higher-order theory survives its trip to Heidelberg. (shrink)

According to higher-order theories of consciousness, a mental state is conscious only when represented by another mental state. Higher-order theories must predict there to be some brain areas (or networks of areas) such that, because they produce (the right kind of) higher-order states, the disabling of them brings about deficits in consciousness. It is commonly thought that the prefrontal cortex produces these kinds of higher-order states. In this paper, I first argue that (...) this is likely correct, meaning that, if some higher-order theory is true, prefrontal lesions should produce dramatic deficits in visual consciousness. I then survey prefrontal lesion data, looking for evidence of such deficits. I argue that no such deficits are to be found, and that this presents a compelling case against higher-order theories. (shrink)

Doerig et al. have set several criteria that theories of consciousness need to fulfill. By these criteria, higher-order theories fare better than most existing theories. But they also argue that higher-order theories may not be able to answer both the ‘small network argument’ and the ‘other systems argument’. In response, we focus on the case of the Perceptual Reality Monitoring theory to explain why higher-order theories do just fine.

A touchstone of much modern theorizing about the mind is the idea, still tac- itly accepted by many, that a state's being mental implies that it's conscious. This view is epitomized in the dictum, put forth by theorists as otherwise di-.

So-called 'dynamic' semantic theories such as Kamp's discourse representation theory and Heim's file change semantics account for such phenomena as cross-sentential anaphora, donkey anaphora, and the novelty condition on indefinites, but compare unfavorably with Montague semantics in some important respects (clarity and simplicity of mathematical foundations, compositionality, handling of quantification and coordination). Preliminary efforts have been made by Muskens and by de Groote to revise and extend Montague semantics to cover dynamic phenomena. We present a new higher-order (...) theory of discourse semantics which improves on their accounts by incorporating a more articulated notion of context inspired by ideas due to David Lewis and to Craige Roberts. On our account, a context consists of a common ground of mutually accepted propositions together with a set of discourse referents preordered by relative salience. Employing a richer notion of contexts enables us to extend our coverage beyond pronominal anaphora to a wider range of presuppositional phenomena, such as the factivity of certain sentential-complement verbs, resolution of anaphora associated with arbitrarily complex definite descriptions, presupposition 'holes' such as negation, and the independence condition on the antecedents of conditionals. Formally, our theory is expressed within a higher-order logic with natural number type, separation-style subtyping, and dependent coproducts parameterized by the natural numbers. The system of semantic types builds on proposals due to Thomason and to Pollard in which the type of propositions (static meanings of sentential utterances) is taken as basic and worlds are constructed from propositions (rather than the other way around as in standard Montague semantics). (shrink)

Abstract: According to a higher-order theory of consciousness, you are in a conscious (psychological) state if and only if you are conscious of being in that state. This paper develops and discusses a Euthyphro dilemma for theories of this sort; that is, a dilemma which asks whether the state is conscious because you are conscious of being in it, or, alternatively, whether you are conscious of being in it because it is conscious. I focus on two different (...) versions of the higher-order theory: the higher-order thought theory, defended by David Rosenthal, Hakwan Lau and Richard Brown, among others, and the higher-order acquaintance theory, defended by Brie Gertler, Martine Nida-Rümelin and David Chalmers, among others. I argue that both versions of the view face a Euthyphro dilemma though the issue takes a different form in each case. (shrink)

**No longer available - article has been replaced by an updated entry.

Higher-order theories account for intransitive consciousness by using the transitive notion ‘awareness-of.’ I argue that this notion implies a form of ‘seeming’ that the higher-order approach requires, yet cannot account for. I show that, if the relevant kind of seeming is declared to be present in all representational states, the seeming in question is objectionably trivialized; while using the higher-order strategy to capture not only intransitive consciousness but also the relevant kind of seeming results (...) in an infinite regress. Finally, highlighting distinctive features of representations that explain why they display seeming amounts to abandoning the higher-order approach altogether. (shrink)

This article addresses the recent reception of Franz Brentano's writings on consciousness. I am particularly interested in the connection established between Brentano's theory of consciousness and higher-order theories of consciousness and, more specifically, the theory proposed by David Rosenthal. My working hypothesis is that despite the many similarities that can be established with Rosenthal's philosophy of mind, Brentano's theory of consciousness differs in many respects from higher-order theories of consciousness and avoids most of (...) the criticisms generally directed to them. This article is divided into eight parts. The first two sections expound the basic outline of Rosenthal's theory, and the third summarizes the principal objections that Rosenthal addresses to Brentano, which I, then, examine in sections 4 and 5. In sections 6 and 7, I discuss Brentano's principle of the unity of consciousness, and in section 8, I consider the scope of the changes that Brentano brings to his theory of consciousness in his later writings, which follow the 1874 publication of Psychology. I then draw the conclusion that Brentano's theory rests on a view of intransitive and intrinsic self-consciousness. (shrink)

Higher Order theories of consciousness have their fair share of sympathisers, but the arguments mustered in their support are—to my mind—unduly persuasive. My aim in this paper is to show that Higher Order theories cannot accommodate the possibility of misrepresentation without either falling into contradiction, or collapsing into a First-Order theory. If this diagnosis is on the right track, then Higher Order theories—at least in the specific versions here considered—fail to give an (...) account of what they set out to explain: what is distinctive of ‘conscious’ phenomena. (shrink)

Some advocates of higher-order theories of consciousness believe that the correct theory of consciousness together with empirical facts about animal intelligence make it highly unlikely that animals are capable of having phenomenally conscious experiences. I will argue that even if the higher-order thought (HOT) theory of consciousness is correct, there is good evidence (taken from experiments in mind reading and metacognition, as well as considerations from neurophysiology and evolutionary biology) that at least some nonhuman (...) animals can form the higher-order thoughts and thus will count as phenomenally conscious on HOT theory. (shrink)

This chapter provides an introduction to higher-order metaphysics as well as to the contributions to this volume. We discuss five topics, corresponding to the five parts of this volume, and summarize the contributions to each part. First, we motivate the usefulness of higher-order quantification in metaphysics using a number of examples, and discuss the question of how such quantifiers should be interpreted. We provide a brief introduction to the most common forms of higher-order logics (...) used in metaphysics, and indicate a number of questions which can be raised in such systems using logical vocabulary alone. Using a further example, we return to applications of higher-order logics in metaphysics. We also mention key developments in the history of higher-order logic as it pertains to metaphysics. Finally, we mention certain arguments which have been raised against the use of higher-order logic, and some ways of responding to them. (shrink)

We present a new account of perceptual consciousness, one which gives due weight to the epistemic commitment of normal perception in familiar circumstances. The account is given in terms of a higher-order attitude for which the subject has an immediate perceptual epistemic warrant in the form of an appropriate first-order perception. We develop our account in contrast to Rosenthal's higher-order account, rejecting his view of consciousness in virtue of so-called ‘targetless’ higher-order states. We (...) explain the key notion of an immediate perceptual warrant and show both that it requires the content of the higher-order attitude to match that of the first-order perception, and also that it gives a new perspective on the intimate relationship, rightly emphasised by Rosenthal, between consciousness and a subject's testimony as to ‘how it is with her’. (shrink)

Proponents of the higher‐order (HO) theory of consciousness (e.g., Lau and Rosenthal) have recently appealed to brain lesion evidence to support their thesis that mental states are conscious when and only when represented by other mental states. This article argues that this evidence fails to support HO theory, doing this by first determining what kinds of conscious deficit should result when HO state‐producing areas are damaged, then arguing that these kinds of deficit do not occur in (...) the studies to which HO theorists appeal. The article also develops an apparatus that can be used to evaluate whether other lesion evidence confirms or disconfirms HO theory. (shrink)

It is usually taken as given that consciousness involves superior or more elaborate forms of information processing. Contemporary models equate consciousness with global processing, system complexity, or depth or stability of computation. This is in stark contrast with the powerful philosophical intuition that being conscious is more than just having the ability to compute. I argue that it is also incompatible with current empirical findings. I present a model that is free from the strong assumption that consciousness predicts superior performance. (...) The model is based on Bayesian decision theory, of which signal detection theory is a special case. It reflects the fact that the capacity for perceptual decisions is fundamentally limited by the presence and amount of noise in the system. To optimize performance, one therefore needs to set decision criteria that are based on the behaviour, i.e. the probability distributions, of the internal signals. One important realization is that the knowledge of how our internal signals behave statistically has to be learned over time. Essentially, we are doing statistics on our own brain. This ‘higherorder’ learning, however, may err, and this impairs our ability to set and maintain optimal criteria for perceptual decisions, which I argue is central to perception consciousness. I outline three possibilities of how conscious perception might be affected by failures of ‘higher-order’ representation. These all imply that one can have a dissociation between consciousness and performance. This model readily explains blindsight and hallucinations in formal terms, and is beginning to receive direct empirical support. I end by discussing some philosophical implications of the model. (shrink)

Due to their reliance on constitutive higher-order representing to generate the qualities of which the subject is consciously aware, I argue that the major existing higher-order representational theories of consciousness insulate us from our first-order sensory states. In fact on these views we are never properly conscious of our sensory states at all. In their place I offer a new higher-order theory of consciousness, with a view to making us suitably intimate with (...) our sensory states in experience. This theory relies on the idea of ‘quoting’ sensory qualities, so is dubbed the ‘quotational higher-order thought theory’. I argue that it can capture something of the idea that we are ‘acquainted’ with our conscious states without slipping beyond the pale for naturalists, whilst also providing satisfying treatments of traditional problems for higher-order theories concerning representational mismatch. The theory achieves this by abandoning a representational mechanism for mental intentionality, in favour of one based on ‘embedding’. (shrink)

ABSTRACT I begin by developing a challenge for the Higher-Order Thought variant of Higher-Order representational theories of consciousness. The challenge is to account for the distinctive phenomenal character of visual experience—its presentational character. After setting out the challenge, I articulate a novel form of Higher-Order theory that can account for presentational character—the Map Theory of consciousness. The theory’s distinctive claim is that the relevant higher-order representations have a cartographic format.

In this article, we will describe higher order thought theories of consciousness. Then we will describe some examples from synesthesia. Finally, we will explain why the latter may be relevant to the former.

Due to their reliance on constitutive higher-order representing to generate the qualities of which the subject is consciously aware, I argue that the major existing higher-order representational theories of consciousness insulate us from our first-order sensory states. In fact on these views we are never properly conscious of our sensory states at all. In their place I offer a new higher-order theory of consciousness, with a view to making us suitably intimate with (...) our sensory states in experience. This theory relies on the idea of ‘quoting’ sensory qualities, so is dubbed the ‘quotational higher-order thought theory’. I argue that it can capture something of the idea that we are ‘acquainted’ with our conscious states without slipping beyond the pale for naturalists, whilst also providing satisfying treatments of traditional problems for higher-order theories concerning representational mismatch. The theory achieves this by abandoning a representational mechanism for mental intentionality, in favour of one based on ‘embedding’. (shrink)

Theories of what it is for a mental state to be conscious must answer two questions. We must say how we're conscious of our conscious mental states. And we must explain why we seem to be conscious of them in a way that's immediate. Thomas Natsoulas distinguishes three strategies for explaining what it is for mental states to be conscious. I show that the differences among those strategies are due to the divergent answers they give to the foregoing questions. Natsoulas (...) finds most promising the strategy that amounts to the higher-order-thought hypothesis that I've defended elsewhere. But he raises a difficulty for it, which he thinks probably can be met only by modifying that strategy. I argue that this is unnecessary. The difficulty is a special case of a general question, the answer to which is independent of any issues about consciousness. So it's no part of a theory of consciousness to address the problem, much less solve it. Moreover, the difficulty seems to have intuitive force only given the picture that underlies the other two explanatory strategies, which both Natsoulas and I reject. (shrink)

This Element is an exposition of second- and higher-order logic and type theory. It begins with a presentation of the syntax and semantics of classical second-order logic, pointing up the contrasts with first-order logic. This leads to a discussion of higher-order logic based on the concept of a type. The second Section contains an account of the origins and nature of type theory, and its relationship to set theory. Section 3 introduces (...) Local Set Theory, an important form of type theory based on intuitionistic logic. In Section 4 number of contemporary forms of type theory are described, all of which are based on the so-called 'doctrine of propositions as types'. We conclude with an Appendix in which the semantics for Local Set Theory - based on category theory - is outlined. (shrink)

Higher-order theories of consciousness, such as those of Armstrong, Rosenthal and Lycan, typically distinguish sharply between consciousness and phenomenal character, or qualia. The higher-order states posited by these theories are intended only as explanations of consciousness, and not of qualia. In this paper I argue that the positing of higher-order perceptions may help to explain qualia. If we are realists about qualia, conceived as those intrinsic properties of our experience of which we are introspectibly (...) aware, then higher-order perception might have an explanatory role as the means by which we are aware of these properties. This would also allow us to treat qualia as the inner appearances resulting from inner perceptions, and therefore to treat them as intentional objects. (shrink)

Higher-order theories of consciousness posit that a mental state is conscious by virtue of being represented by another mental state, which is therefore a higher-order representation (HOR). Whether HORs are construed as thoughts or experiences, higher-order theorists have generally contested whether such metarepresentations have any significant cognitive function. In this paper, I argue that they do, focusing on the value of conscious thinking, as distinguished from conscious perceiving, conscious feeling, and other forms of conscious (...) mentality. A thinking process is constituted by propositional-attitude states, and during conscious thinking some or all of these states would be targeted by HORs. Since cases of nonconscious thinking are widely accepted, the question arises as to the use of representing one's thoughts during thinking. Contra the views of Armstrong and Rolls, I argue that HORs do not facilitate first-order thinking. Rather, I propose that such representations enable reasoning about one's act of thinking, and I give various examples of this sort of metacognition in support of the theory. I further argue that the general correlation between complex thinking and its being conscious is merely due to the fact that assessing one's mental act is particularly useful during such thinking, not because consciousness somehow facilitates first-order inference-making, as folk psychology implies. My view is thus consistent with recent empirical evidence that complex thinking sometimes yields better results when nonconscious. (shrink)

Higher-order representation (HOR) theories posit that the contents of lower-order brain states enter consciousness when tracked by a higher-order brain state. The nature of higher-order monitoring was examined in light of current scientific knowledge, primarily in experimental perceptual psychology. The most plausible candidate for higher-order state was found to be conceptual short-term memory (CSTM), a buffer memory intimately connected with a semantic engine operating in the medium of the language of thought (...) (LOT). This combination meets many of the requirements of HOR theories, although falling short in some significant respects, most notably the inability of higher- order states to represent more than a small fraction of the information contained in primary states, especially in vision. A possible way round this obstacle is suggested, involving the representation of visual detail by means of ensemble concepts. (shrink)

According to higher order theories of consciousness, a mental state is conscious when there is a HO state about it. However, some HO states do not seem to be about other existing mental states. It is possible to resolve this problem since targetless HO states resemble HO states that misrepresent but the assumption that HO states always target other existing mental states is at odds with the theory since HO states are not only necessary but also sufficient (...) for phenomenal consciousness according to the theory. Given the sufficiency of the HO states for consciousness, there is a need to understand the emergence of HO states as a non-random phenomenon to avoid the difficulties caused by targetless HO states. I suggest it is possible to develop such an understanding by thinking of HO states as predictive states in accordance with the predictive processing theory of the mind. (shrink)

This chapter explores the metaphysical views about higher-order logic held by two individuals responsible for introducing it to philosophy: Gottlob Frege (1848–1925) and Bertrand Russell (1872–1970). Frege understood a function at first as the remainder of the content of a proposition when one component was taken out or seen as replaceable by others, and later as a mapping between objects. His logic employed second-order quantifiers ranging over such functions, and he saw a deep division in nature between (...) objects and functions. Russell understood propositional functions as what is obtained when constituents of propositions are replaced by variables, but eventually denied that they were entities in their own right. Both encountered contradictions when supposing there to exist as many objects as functions, and both adopted views about the meaningfulness of higher-order discourse that were difficult to state from within their own strictures. (shrink)

Quantum interference, manifest in the two slit experiment, lies at the heart of several quantum computational speed-ups and provides a striking example of a quantum phenomenon with no classical counterpart. An intriguing feature of quantum interference arises in a variant of the standard two slit experiment, in which there are three, rather than two, slits. The interference pattern in this set-up can be written in terms of the two and one slit patterns obtained by blocking one, or more, of the (...) slits. This is in stark contrast with the standard two slit experiment, where the interference pattern cannot be written as a sum of the one slit patterns. This was first noted by Rafael Sorkin, who raised the question of why quantum theory only exhibits irreducible interference in the two slit experiment. One approach to this problem is to compare the predictions of quantum theory to those of operationally-defined ‘foil’ theories, in the hope of determining whether theories that do exhibit higher-order interference suffer from pathological—or at least undesirable—features. In this paper two proposed extensions of quantum theory are considered: the theory of Density Cubes proposed by Dakić, Paterek and Brukner, which has been shown to exhibit irreducible interference in the three slit set-up, and the Quartic Quantum Theory of Życzkowski. The theory of Density Cubes will be shown to provide an advantage over quantum theory in a certain computational task and to posses a well-defined mechanism which leads to the emergence of quantum theory—analogous to the emergence of classical physics from quantum theory via decoherence. Despite this, the axioms used to define Density Cubes will be shown to be insufficient to uniquely characterise the theory. In comparison, Quartic Quantum Theory is a well-defined theory and we demonstrate that it exhibits irreducible interference to all orders. This feature of Życzkowski’s theory is argued not to be a genuine phenomenon, but to arise from an ambiguity in the current definition of higher-order interference in operationally-defined theories. Thus, to begin to understand why quantum theory is limited to a certain kind of interference, a new definition of higher-order interference is needed that is applicable to, and makes good operational sense in, arbitrary operationally-defined theories. (shrink)

The systems Kα of transfinite cumulative types up to α are extended to systems K∞α that include a natural infinitary inference rule, the so-called limit rule. For countable α a semantic completeness theorem for K∞α is proved by the method of reduction trees, and it is shown that every model of K∞α is equivalent to a cumulative hierarchy of sets. This is used to show that several axiomatic first-order set theories can be interpreted in K∞α, for suitable α.

This article reports that some robustness of the notions of predicativity and of autonomous progression is broken down if as the given infinite total entity we choose some mathematical entities other than the traditionalω. Namely, the equivalence between normal transfinite recursion scheme and newdependent transfinite recursionscheme, which does hold in the context of subsystems of second order number theory, does not hold in the context of subsystems of second order set theory where the universeVof sets is (...) treated as the given totality. (shrink)

W. V. Quine famously defended two theses that have fallen rather dramatically out of fashion. The first is that intensions are “creatures of darkness” that ultimately have no place in respectable philosophical circles, owing primarily to their lack of rigorous identity conditions. However, although he was thoroughly familiar with Carnap’s foundational studies in what would become known as possible world semantics, it likely wouldn’t yet have been apparent to Quine that he was fighting a losing battle against intensions, due in (...) large measure to developments stemming from Carnap’s studies and culminating in the work of Kripke, Hintikka, and Bayart. These developments undermined Quine’s crusade against intensions on two fronts. First, in the context of possible world semantics, intensions could after all be given rigorous identity conditions by defining them (in the simplest case) as functions from worlds to appropriate extensions, a fact exploited to powerful and influential effect in logic and linguistics by the likes of Kaplan, Montague, Lewis, and Cresswell. Second, the rise of possible world semantics fueled a strong resurgence of metaphysics in contemporary analytic philosophy that saw properties and propositions widely, fruitfully, and unabashedly adopted as ontological primitives in their own right. This resurgence — happily, in my view — continues into the present day. -/- For a time, at any rate, Quine experienced somewhat better success with his second thesis: that higher-order logic is, at worst, confused and, at best, a quirky notational alternative to standard first-order logic. However, Quine notwithstanding, a great deal of recent work in formal metaphysics transpires in a higher-order logical framework in which properties and propositions fall into an infinite hierarchy of types of (at least) every finite order. Initially, the most philosophically compelling reason for embracing such a framework since Russell first proposed his simple theory of types was simply that it provides a relatively natural explanation of the paradoxes. However, since the seminal work of Prior there has been a growing trend to consider higher-order logic to be the most philosophically natural framework for metaphysical inquiry, many of the contributors to this volume being among the most important and influential advocates of this view. Indeed, this is now quite arguably the dominant view among formal metaphysicians. -/- In this paper, and against the current tide, I will argue in §1 that there are still good reasons to think that Quine’s second battle is not yet lost and that the correct framework for logic is first-order and type-free — properties and propositions, logically speaking, are just individuals among others in a single domain of quantification — and that it arises naturally out of our most basic logical and semantical intuitions. The data I will draw upon are not new and are well-known to contemporary higher-order metaphysicians. However, I will try to defend my thesis in what I believe is a novel way by suggesting that these basic intuitions ground a reasonable distinction between “pure” logic and non-logical theory, and that Russell-style semantic paradoxes of truth and exemplification arise only when we move beyond the purely logical and, hence, do not of themselves provide any strong objection to a type-free conception of properties and propositions. -/- Most of my arguments in §1 are largely independent of any specific account of the nature of properties and propositions beyond their type-freedom. However, I will in addition argue that there are good reasons to take propositions, at least, to be very fine-grained. My arguments are thus bolstered significantly if it can be shown that there are in fact well-defined examples of logics that are not only type-free but which comport with such a conception of propositions. It is the purpose of §2 to lay out a logic of this sort in some detail, drawing especially upon work by George Bealer and related work of my own. With the logic in place, it will be possible to generalize the line of argument noted above regarding Russell-style paradoxes and, in §3, apply it to two propositional paradoxes — the Prior-Kaplan paradox and the Russell-Myhill paradox — that are often taken to threaten the sort of account developed here. (shrink)

Josh Weisberg discusses what he calls the “Heidelberg Problem” (named after Dieter Henrich’s Heidelberg School). However, he mischaracterizes this problem and believes he is able so resolve the problem, as mischaracterized, as well as meet the de se constraint, in the theoretical frame of reference of the Higher-Order Thought Monitoring theory of consciousness. This commentary highlights the fundamental flaw in his approach, while encouraging further philosophical exchange with our American philosophical colleagues about the “Heidelberg Problem”.

The massive debate in philosophy and psychology and neuroscience about higher-order theories of consciousness has not adequately distinguished between the following two claims. (Necessary Awareness): For any conscious mental state M and subject S, if S is in M, then S is aware of M. (The Higher-Order Theory): For any conscious mental state M and subject S, if S is in M, then M is conscious because S is aware of M. -/- While I will (...) assume that the first claim is true, I will argue that we should reject higher-order theories of consciousness. We should turn them on their head to go with the following theory: (The Ascending Road): For any conscious mental state M and subject S, if S is in M, then S is aware of M because M is conscious. (shrink)