Zhiwei Gu

A long-standing theme in discussion of perception and thought has been that our primary cognitive contact with individual objects and events in the world derives from our perceptual contact with them. When I look at a duck in front of me, I am not merely presented with the fact that there is at least one duck in the area, rather I seem to be presented withthisthing (as one might put it from my perspective) in front of me, which looks to me to be a duck. Furthermore, such a perception would seem to put me in a position not merely to make the existential judgment that there is some duck or other present, but rather to make a singular, demonstrative judgment, that that is a duck. My grounds for an existential judgment in this case derives from my apprehension of the demonstrative thought and not vice versa.

Many contemporary theorists charge that naïve realists are incapable of accounting for illusions. Various sophisticated proposals have been ventured to meet this charge. Here, we take a different approach and dispute whether the naïve realist owes any distinctive account of illusion. To this end, we begin with a simple, naïve account of veridical perception. We then examine the case that this account cannot be extended to illusions. By reconstructing an explicit version of this argument, we show that it depends critically on the contention that perceptual experience is diaphanous, or more minimally and precisely, that there can be no difference in phenomenal properties between two experiences without a difference in the scenes presented in those experiences. Finding no good reason to accept this claim, we develop and defend a simple, naïve account of both veridical perception and illusion, here dubbed Simple, Austere Naïve Realism.

A recurring theme dominates recent philosophical debates about the nature of conscious perception: naïve realism’s opponents claim that the view is directly contradicted by empirical science. I argue that, despite their current popularity, empirical arguments against naïve realism are fundamentally flawed. The non-empirical premises needed to get from empirical scientific findings to substantive philosophical conclusions are ones the naïve realist is known to reject. Even granting the contentious premises, the empirical findings do not undermine the theory, given its overall philosophical commitments. Thus, contemporary empirical research fails to supply any new argumentative force against naïve realism. I conclude that, as philosophers of mind, we would be better served spending a bit less time trying to wield empirical science as a cudgel against our opponents, and a bit more time working through the implications of each other’s views – something we can accomplish perfectly well from the comfort of our armchairs.

The Reichenbach-Grunbaum thesis of the conventionality of simultaneity is clarified and defended by developing the consequences of the Special Theory when assumptions are not made concerning the one-way speed of light. It is first shown that the conventionality of simultaneity leads immediately to the conventionality of all relative speeds. From this result, the general-length-contraction and time-dilation relations are then derived. Next, the place of time-dilation and length-contraction effects within the Special Theory is examined in the light of the conventionality thesis. The slow-transport method of synchrony is then examined in the light of these results and is shown not to provide an adequate method of uniquely determining the one-way speed of light. Finally, the general ε -Lorentz transformations for events along the x-axis are derived from three principles: the round-trip light principle, the principle of equal passage times, and the linearity principle. These principles are shown to be independent of one-way velocity assumptions, and thus may form the basis of a Special Theory of Relativity without distant simultaneity assumptions

Fish proposes that we need to elucidate what 'disjunctivism' stands for, and he also proposes that it stands for the rejection of a principle about the nature of experience that he calls the decisiveness principle. The present paper argues that his first proposal is reasonable, but then argues, in Section II, that his positive suggestion does not draw the line between disjunctivism and non-disjunctivism in the right place. In Section III, it is argued that disjunctivism is a thesis about the special nature of perceptual experience, and the thesis as elucidated here is then distinguished from and related to certain other ideas about perception, namely, direct realism and also McDowell's epistemological disjunctivism

In The Mind and the World Order, C.I. Lewis made a famous distinction between the immediate data ‘which are presented or given to the mind’ and the ‘construction or interpretation’ which the mind brings to those data (1929: 52). What the mind receives is the datum – literally, the given – and the interpretation is what happens when we being it ‘under some category or other, select from it, emphasise aspects of it, and relate it in particular and unavoidable ways’ (1929: 52). So although any attempt to describe the given will inevitably be an interpretation of it, this should not give us reason to deny its existence: ‘no-one but a philosopher could for a moment deny this immediate presence in consciousness of that which no activity of thought can create or alter’ (1929: 53). Whatever those outside philosophy might think, Lewis was certainly right about what philosophers were prepared to deny. His conception of the ‘given’ is without question one of the targets of Wilfrid Sellars’s influential critique of the notion of the ‘whole framework of givenness’ (1957).1 One of the things Sellars was attacking was the idea that something that was merely given by the senses could put one in a position to be justified in making a judgement about the empirical world. The..

Sense data are the alleged mind-dependent objects that we are directly aware of in perception, and that have exactly the properties they appear to have. For instance, sense data theorists say that, upon viewing a tomato in normal conditions, one forms an image of the tomato in one's mind. This image is red and round. The mental image is an example of a “sense datum.” Many philosophers have rejected the notion of sense data, either because they believe that perception gives us direct awareness of physical phenomena, rather than mere mental images, or because they believe that the mental phenomena involved in perception do not have the properties that appear to us (for instance, I might have a visual experience representing a red, round tomato, but my experience is not itself red or round). Defenders of sense data have argued, among other things, that sense data are required to explain such phenomena as perspectival variation, illusion, and hallucination. Critics of sense data have objected to the theory's commitment to mind-body dualism, the problems it raises for our knowledge of the external world, its difficulty in locating sense data in physical space, and its apparent commitment to the existence of objects with indeterminate properties

It is widely agreed that perceptual experience is a form of intentionality, i.e., that it has representational content. Many philosophers take this to mean that like belief, experience has propositional content, that it can be true or false. I accept that perceptual experience has intentionality; but I dispute the claim that it has propositional content. This claim does not follow from the fact that experience is intentional, nor does it follow from the fact that experiences are accurate or inaccurate. I end by considering the relationship between this question and the question of whether experience has non-conceptual content.

I aim to draw the reader's attention to an easily overlooked account of perception, namely that there are no perceptual experiences, that to perceive something is to stand in an external, purely non-Leibnizian relation to it. I introduce the Purely Relational account of perception by discussing a case of it being overlooked in the writings of G.E. Moore, though we also find the same move in J. Cook Wilson, so it has nothing to do with an affection for sense-data. I then discuss the relation between the PR account and recent disjunctive accounts of perceptual experience, and note that the PR account has some claim to be the only one that truly respects the directness of perception. The paper does not aspire to persuade the reader of the correctness of the neglected PR account, merely that it should be treated as a serious candidate in philosophical debates about perception.

The disjunctive theory of perception claims that we should understand statements about how things appear to a perceiver to be equivalent to statements of a disjunction that either one is perceiving such and such or one is suffering an illusion (or hallucination); and that such statements are not to be viewed as introducing a report of a distinctive mental event or state common to these various disjoint situations. When Michael Hinton first introduced the idea, he suggested that the burden of proof or disproof lay with his opponent, that what was needed was to show that our talk of how things look or appear to one..

There is a view abroad on which perceptual experience has representational content in this sense: in it something is represented to the perceiver as so. On the view, a perceptual experience has a face value at which it may be taken, or which may be rejected. This paper argues that that view is mistaken: there is nothing in perceptual experience which makes it so that in it anything is represented as so. In that sense, the senses are silent, or, in Austin's term, dumb. Perceptual experience is not as such either veridical or delusive. It may mislead, but it does not take representation to accomplish that

Questions about perception remain some of the most difficult and insoluble in both epistemology and in the philosophy of mind. This controversial but highly accessible introduction to the area explores the philosophical importance of those questions by re-examining what had until recent times been the most popular theory of perception - the sense-datum theory. Howard Robinson surveys the history of the arguments for and against the theory from Descartes to Husserl. He then shows that the objections to the theory, particularly Wittgenstein's attack on privacy and those of the physicalists, have been unsuccessful. He argues that we should return to the theory sense-data in order to understand perception. In doing so he seeks to overturn a consensus that has dominated the philosophy of perception for nearly half a century.

This paper sets out a novel response to the ‘screening off problem’ for naïve realism. The aim is to resist the claim (which many naïve realists accept) that the kind of experience involved in hallucinating also occurs during perception, by arguing that there are causal constraints that must be met if an hallucinatory experience is to occur that are never met in perceptual cases. Notably, given this response, it turns out that, contra current orthodoxy, naïve realists need not adopt any particular view about the psychological nature of hallucinatory experience to handle the screening off problem. Consequently, room opens up for naïve realists to endorse whatever theory of hallucinatory experience seems to best capture the distinctive nature of such episodes.

What are hallucinations? A common view in the philosophical literature is that hallucinations are degenerate kinds of perceptual experience. I argue instead that hallucinations are degenerate kinds of sensory imagination. As well as providing a good account of many actual cases of hallucination, the view that hallucination is a kind of imagination represents a promising account of hallucination from the perspective of a disjunctivist theory of perception like naïve realism. This is because it provides a way of giving a positive characterisation of hallucination—rather than characterising hallucinations in negative, relational, terms as mental events that are subjectively indistinguishable from veridical perceptual experiences.

Early modern empiricists thought that the nature of perceptual experience is given by citing the object presented to the mind in that experience. Hallucination and illusion suggest that this requires untenable mind-dependent objects. Current orthodoxy replaces the appeal to direct objects with the claim that perceptual experience is characterized instead by its representational content. This paper argues that the move to content is problematic, and reclaims the early modern empiricist insight as perfectly consistent, even in cases of illusion, with the realist contention that these direct objects of perception are the persisting mind-independent physical objects we all know and love.