The illusion of conscious will

Wegner (Wegner, D. (2002). The illusion of conscious will. MIT Press) argues that conscious will is an illusion, citing a wide range of empirical evidence. I shall begin by surveying some of his arguments. Many are unsuccessful. But one—an argument from the ubiquity of self-interpretation—is more promising. Yet is suffers from an obvious lacuna, offered by so-called ‘dual process’ theories of reasoning and decision making (Evans, J., &; Over, D. (1996). Rationality and reasoning. Psychology Press; Stanovich, K. (1999). Who is rational? Studies of individual differences in reasoning. Lawrence Erlbaum; Frankish, K. (2004). Mind and supermind. Cambridge University Press). I shall argue that this lacuna can be filled by a plausible a priori claim about the causal role of anything deserving to be called ‘a will.’ The result is that there is no such thing as conscious willing: conscious will is, indeed, an illusion.     

On A. D. Smith’s constancy based defence of direct realism

This paper presents an argument against A D Smith’s Direct Realist theory of perception, which attempts to defend Direct Realism against the argument from illusion by appealing to conscious perceptual states that are structured by the perceptual constancies. Smith’s contention is that the immediate objects of perceptual awareness are characterised by these constancies, which removes any difficulty there may be in identifying them with the external, or normal, objects of awareness. It is here argued that Smith’s theory does not provide an adequate defence of Direct Realism because it does not adequately deal with the difficulties posed by the possibility of perceptual illusion. It is argued that there remain possible illusory experiences where the immediate objects of awareness, which in Smith’s account are those characterised by perceptual constancies, cannot be identified with the external objects of awareness, contrary to Direct Realism. A further argument is offered to extend this conclusion to all non-illusory cases, by adapting an argument of Smith’s own for the generalising step of the Argument from Illusion. The result is that Smith’s theory does not provide an adequate Direct Realist account of the possibility of perceptual illusion.     

The role of apparent distance in the Poggendorff illusion

This study was designed to test the hypothesis that apparent shrinkage of the distance between the oblique lines is responsible for the Poggendorff illusion. The results from one experiment, which provided an indirect test by increasing the length of the oblique arm, supported the shrinkage hypothesis. However, a second experiment, in which apparent distance was measured directly, did not support the hypothesis. Instead, the distance between the oblique lines appeared longer than a control distance. It was concluded that the argument, made by assimilation theory, that the Poggendorff illusion is caused by changes in the apparent distance between oblique lines must be reassessed.     

Scepticism About Scepticism or the Very Idea of a Global ‘Vat-Language’

This paper aims to motivate a scepticism about scepticism in contemporary epistemology. I present the sceptic with a dilemma: On one parsing of the BIV (brain-in-a-vat) scenario, the second premise in a closure-based sceptical argument will turn out false, because the scenario is refutable; on another parsing, the scenario collapses into incoherence, because the sceptic cannot even save the appearances. I discuss three different ways of cashing out the BIV scenario: ‘Recent Envatment’ (RE), ‘Lifelong Envatment’ (LE) and ‘Nothing But Envatment’ (NBE). I show that RE scenarios are a kind of ‘local’ sceptical scenario that does not pose a significant threat to the possibility of perceptual knowledge as such. I then go on to consider the more radical (or global) LE and NBE scenarios, which do undermine the possibility of perceptual knowledge of an ‘external’ world by positing that it is conceivable that one has always been envatted and, hence, trapped in a ‘global’ illusion. I start by assuming that we could be in such a scenario (LE or NBE) and then spell out what we would need to presuppose for such scenarios to be capable of being actual. Drawing on some central insights from Wittgenstein’s anti-private language considerations, I show that the truth of a global scepticism would presuppose the possibility of a private ‘vat-language’, a notion that cannot be rendered coherent. But, if so, then neither can the sceptical scenarios that presuppose such a conception.

     

From nihilism to monism

McDowell has argued that external world scepticism is a pressing problem only in so far as we accept, on the basis of the argument from illusion, the claim that perceiving that p and hallucinating that p involve a highest common factor--something which functions, in the manner of the classical 'veil of ideas', as a perceptual intermediary. McDowell traces the power of this argument to disputable Cartesian assumptions about the transparency of subjectivity to itself. I argue, contra McDowell, that the reflections to be found in, paradigmatically, Descartes's First Meditation are better interpreted as offering a causal argument for scepticism that depends upon a naturalistic conception of sense experience. This is more powerful than the argument from illusion, since it requires no commitment to a highest common factor in perception, nor to the transparency of the mental. The availability of this alternative route to scepticism raises serious problems for McDowell's quietism, which aims to earn the right to avoid, rather than answer, the sceptic. Since the appeal to externalism about content cannot settle the matter, I conclude that there is, at present, an unsatisfactory stand-off between the sceptic and McDowell's position.     

Materialism and the Subjectivity of Experience

The phenomenal properties of conscious mental states happen to be exclusively accessible from the first-person perspective. Consequently, some philosophers consider their existence to be incompatible with materialist metaphysics. In this paper I criticise one particular argument that is based on the idea that for something to be real it must (at least in principle) be accessible from an intersubjective perspective. I argue that the exclusively subjective access to phenomenal contents can be explained by the very particular nature of the epistemological relation holding between a subject and his own mental states. Accordingly, this subjectivity does not compel us to deny the possibility that phenomenal contents are ontologically objective properties. First, I present the general form of the argument that I will discuss. Second, I show that this argument makes use of a criterion of reality that is not applicable to the case of subjective experience. Third, I discuss a plausible objection and give an argument for rejecting observation models of self-knowledge of phenomenal contents. These models fall prey to the homunculus illusion.     

The Müller-Lyer illusion in touch and vision: implications for multisensory processes

In six experiments, we used the Müller-Lyer illusion to investigate factors in the integration of touch, movement, and spatial cues in haptic shape perception, and in the similarity with the visual illusion. Latencies provided evidence against the hypothesis that scanning times explain the haptic illusion. Distinctive fin effects supported the hypothesis that cue distinctiveness contributes to the illusion, but showed also that it depends on modality-specific conditions, and is not the main factor. Allocentric cues from scanning an external frame (EF) did not reduce the haptic illusion. Scanning elicited downward movements and more negative errors for horizontal convergent figures and more positive errors for vertical divergent figures, suggesting a modality-specific movement effect. But the Müller-Lyer illusion was highly significant for both vertical and horizontal figures. By contrast, instructions to use body-centered reference and to ignore the fins reduced the haptic illusion for vertical figures in touch from 12.60% to 1.7%. In vision, without explicit egocentric reference, instructions to ignore fins did not reduce the illusion to near floor level, though external cues were present. But the visual illusion was reduced to the same level as in touch with instructions that included the use of body-centered cues. The new evidence shows that the same instructions reduced the Müller-Lyer illusion almost to zero in both vision and touch. It suggests that the similarity of the illusions is not fortuitous. The results on touch supported the hypothesis that body-centered spatial reference is involved in integrating inputs from touch and movement for accurate haptic shape perception. The finding that explicit egocentric reference had the same effect on vision suggests that it may be a common factor in the integration of disparate inputs from multisensory sources.     

Sighting-down and the Poggendorff illusion: a mystery within a mystery.

As reported before, sighting-down one of the diagonal lines on a typical Poggendorff pattern will reduce the illusion even if that situation is only pictorial. But here it is also argued that sighting-down itself requires further understanding.     

The distorted room illusion, equivalent configurations, and the specificity of static optic arrays

The distorted room illusion (DRI) and the attendant argument for perceptual ambiguity is critically analyzed from a Gibsonian/ecological point of view. The notions of multiple specification, conflicting information, and perceptual skill are invoked in showing how the ecological approach can accommodate illusion effects that may remain under mobile binocular viewing conditions. Static optic arrays are shown not to be ambiguous. So-called equivalent configurations are found to be analytic artifacts, appearing when the problem of information is treated in geometrical terms without regard for constraints due to physical and ecological regularities. The relative importance of motion-based and motion-independent information is discussed.     

Relativism and Two Kinds of Branching Time

This essay examines the case for relativism about future contingents in light of a distinction between two ways of interpreting the ‘branching time’ framework. The first step of the relativist argument is to argue for the ‘Non-Determination Thesis’, the view that there is no unique actual future. The second step is to argue from the Non-Determination Thesis to relativism. I show that first step of this argument fails. But despite that result, the second step is still of interest, because one might hold the Non-Determination Thesis on alternative grounds. I then argue that whether the second step of the argument succeeds depends on how the branches in question are interpreted. If the branches are ersatz possible worlds, then the argument for relativism might go through. But if the branches are concrete parts of a ‘branching multiverse’, then the argument for relativism turns out to make implausible assumptions about the nature of personal identity over time.     

A test of the spatial-frequency explanation of the Müller-Lyer illusion

Previous investigations have shown that the response of spatial-frequency-specific channels in the human visual system is differentially affected by adaptation to gratings of distinct spatial frequencies and/or orientations. A study is reported of the effects of adaptation to vertical or horizontal gratings of a high or a low spatial frequency on the extent of the Brentano form of the Müller-Lyer illusion in human observers. It is shown that the illusion decreases after adaptation to vertical gratings of low spatial frequency, but seems unaffected otherwise. These results are consistent with the notion of visual channels that are spatial-frequency and orientation specific, and support the argument that the Müller-Lyer illusion may be due primarily to lower-spatial-frequency components in the Fourier spectra of the image.     

VAGUE PARTS AND VAGUE IDENTITY

We discuss arguments against the thesis that the world itself can be vague. The first section of the paper distinguishes dialectically effective from ineffective arguments against metaphysical vagueness. The second section constructs an argument against metaphysical vagueness that promises to be of the dialectically effective sort: an argument against objects with vague parts. Firstly, cases of vague parthood commit one to cases of vague identity. But we argue that Evans' famous argument against will not on its own enable one to complete the reductio in the present context. We provide a metaphysical premise that would complete the reductio, but note that it seems deniable. We conclude by drawing general morals from our case study.     

Ponzo错觉解释的合理性：倾斜恒常性理论的局限

倾斜恒常性理论是一种新的解释Ponzo错觉的理论,但是似乎存在一些局限。本研究采用调节法通过两个实验考察了四种Ponzo错觉版本在各种条件(视角和水平线段间距)下的错觉量情况,以此来检验倾斜恒常性理论。实验一中,对称Ponzo错觉变异版本在50mm时的错觉量情况和Prinzmetal(2001)的结果相似,但是在85mm和120mm时得到了较多的错觉量,这和倾斜恒常性理论的理论预期不符。实验二对不对称Ponzo错觉的考察得到了和实验一类似的结果,只有50mm时的情形符合倾斜恒常性理论预期。通过以上实验得到水平线间距和视角因素都是产生Ponzo错觉的重要因素,而倾斜恒常性理论过分强调了背景线的倾斜诱导效应,忽略了其他结构因素对Ponzo错觉的影响,所以倾斜恒常性理论具有一定的局限性,不能有效地解释Ponzo错觉的产生机制。     

REPRESENTATIONALISM AND THE ARGUMENT FROM HALLUCINATION

Abstract: Representationalism is sometimes advertised as providing a novel response to the argument from hallucination, one that accepts the presence of a 'common factor' between veridical and hallucinatory experience without positing sensory intermediaries between the mind and the world. I argue that much of the attractiveness of representationalism stems from a failure in the literature to distinguish between two distinct possible versions of representationalism, what I call 'content-based representationalism' and 'vehicle-based representationalism'. Generically, representationalism appears to have a response to the argument from hallucination that avoids a commitment to qualia or sense-data. But once the distinction between content-based representationalism and vehicle-based representationalism is recognized, this response to the argument from hallucination fails.     

Grasping visual illusions: no evidence for a dissociation between perception and action

Neuropsychological studies prompted the theory that the primate visual system might be organized into two parallel pathways, one for conscious perception and one for guiding action. Supporting evidence in healthy subjects seemed to come from a dissociation in visual illusions: In previous studies, the Ebbinghaus (or Titchener) illusion deceived perceptual judgments of size, but only marginally influenced the size estimates used in grasping. Contrary to those results, the findings from the present study show that there is no difference in the sizes of the perceptual and grasp illusions if the perceptual and grasping tasks are appropriately matched. We show that the differences found previously can be accounted for by a hitherto unknown, nonadditive effect in the illusion. We conclude that the illusion does not provide evidence for the existence of two distinct pathways for perception and action in the visual system.     

The second me: Seeing the real body during humanoid robot embodiment produces an illusion of bi-location

Whole-body embodiment studies have shown that synchronized multi-sensory cues can trick a healthy human mind to perceive self-location outside the bodily borders, producing an illusion that resembles an out-of-body experience (OBE). But can a healthy mind also perceive the sense of self in more than one body at the same time? To answer this question, we created a novel artificial reduplication of one’s body using a humanoid robot embodiment system. We first enabled individuals to embody the humanoid robot by providing them with audio-visual feedback and control of the robot head movements and walk, and then explored the self-location and self-identification perceived by them when they observed themselves through the embodied robot. Our results reveal that, when individuals are exposed to the humanoid body reduplication, they experience an illusion that strongly resembles heautoscopy, suggesting that a healthy human mind is able to bi-locate in two different bodies simultaneously.     

Do Near-Death Experiences Provide a Rational Basis for Belief in Life after Death?

In this paper I suggest that near-death experiences (NDEs) provide a rational basis for belief in life after death. My argument is a simple one and is modeled on the argument from religious experience for the existence of God. But unlike the proponents of the argument from religious experience, I stop short of claiming that NDEs prove the existence of life after death. Like the argument from religious experience, however, my argument turns on whether or not there is good reason to believe that NDEs are authentic or veridical. I argue that there is good reason to believe that NDEs are veridical and that therefore it is reasonable to believe in the existence of what they seem to be experiences of, namely, a continued state of consciousness after the death of the body. I will then offer some comments on the philosophical import of NDEs, as well as reflections on the current state of contemporary philosophy in light of the neglect of this phenomenon.     

Observer‐relative chances and the doomsday argument

Suppose various observers are divided randomly into two groups, a large and a small. Not knowing into which group anyone has been sent, each can have strong grounds for believing in being in the large group, although recognizing that every observer in the other group has equally powerful reasons for thinking of this other group as the large one. Justified belief can therefore be observer‐relative in a rather paradoxical way. Appreciating this allows one to reject an intriguing new objection against Brandon Carter's ‘doomsday argument’. Carter encourages us to doubt that we are among only the first hundredth, say, or first millionth, of all humans who will ever have existed. He thereby reinforces whatever reasons we may have for suspecting that, unless we take great care, the human race will not survive long. Admittedly his argument is weakened if our world is indeterministic, so that there is no suitably guaranteed ‘fact of the matter’ of how many humans will ever have existed. But even then, it can caution us against believing that a lengthy future for humankind ‘is as good as determined’. Of all the objections the argument has yet faced, the new one is the most interesting.     

Michael Huemer’s A Priori Defense of Metaethical Internalism

Versions of internalism have played important roles in metaethics, for example, in defending irrealist options such as emotivism. However, internalism is itself as controversial as the views it is used to defend. Standard approaches to testing the view, such as thought experiments about amoralists, have failed to gain consensus. Michael Huemer offers a defense of internalism of a different kind which he calls the “argument from interpretation.” He presents the argument as one Humeans could embrace, but versions could be accepted by others, including Huemer himself. The argument begins from the assumption that a certain principle of charity is true and knowable a priori. But it can only be known a priori if internalism is true. Hence internalism is true. In this paper I argue that this important argument fails. My main objection makes use of recent work in empirical psychology. Huemer needs the principle of charity to be known a priori. I argue that rather than being an a priori issue, it is an empirical one and that the empirical evidence is strong enough to undermine his argument for internalism.     

‘Can’ and the Consequence Argument

The consequence argument is a powerful incompatibilist argument for the conclusion that, if determinism is true, what one does is what one must do. A major point of controversy between classical compatibilists and incompatibilists has been over the use of ‘can’ in the consequence argument. Classical compatibilists, holding that abilities to act are dispositions, have argued that ‘can’ should be analyzed as a conditional. But such an analysis of ‘can’ puts compatibilists in a position to grant the premises of the argument while denying the conclusion. Incompatibilists remain unconvinced, and this corner of the debate over free will has reached a dialectical impasse. The present paper has two aims. First, to offer a new dialectical point of entry into this dispute on behalf of incompatibilists. By making use of Angelika Kratzer's influential semantic work on ‘can’ and ‘must’, I argue that incompatibilists are in a position to offer a plausible, positive treatment of ‘can’ that favors their view. Second, even if one does not think incompatibilism is thereby true (for as we shall see there are places to push back), the Kratzer semantics yields a number of important insights concerning the consequence argument that should be of broad interest. ¹