Online research in philosophy

Since our visual perception of physical things essentially involves our identifying objects by their colours, any theory of visual perception must contain some account of the colours of things. The central problem with colour has to do with relating our normal, everyday colour perceptions to what science, i.e. physics, teaches us about physical objects and their qualities. Although we perceive colours as categorical surface properties of things, colour perceptions are explained by introducing physical properties like reflectance profiles or dispositions to cause certain experiences in normal human perceivers. Hence, it seems as if colours as they are experienced by us have no place in the physical world, because they are fundamentally different from the properties which we ascribe to physical objects in scientific accounts of colour perceptions. This special issue on perspectives on colour perception presents new suggestions to solve to this major problem.

Whether or not we would be happy to do without sounds, the idea that our expe- rience of sounds is of things which are distinct from the world of material objects can seem compelling. All you have to do to confirm it is close your eyes and reflect on the character of your auditory experience.

Tim Crane University College London 1. Introduction P.F. Strawson argued that ‘mature sensible experience (in general) presents itself as … an immediate consciousness of the existence of things outside us’ (1979: 97). He began his defence of this very natural idea by asking how someone might typically give a description of their current visual experience, and offered this example of such a description: ‘I see the red light of the setting sun filtering through the black and thickly clustered branches of the elms; I see the dappled deer grazing in groups on the vivid green grass…’ (1979: 97). In other words, in describing experience, we tend to describe the objects of experience – the things which we experience – and the ways they are when we are experiencing them.

P.F. Strawson argued that ‘mature sensible experience (in general) presents itself as … an immediate consciousness of the existence of things outside us’ (1979: 97). He began his defence of this very natural idea by asking how someone might typically give a description of their current visual experience, and offered this example of such a description: ‘I see the red light of the setting sun filtering through the black and thickly clustered branches of the elms; I see the dappled deer grazing in groups on the vivid green grass…’ (1979: 97). In other words, in describing experience, we tend to describe the objects of experience – the things which we experience – and the ways they are when we are experiencing them. Some go further. According to Heidegger.

Philosophical (p-) zombies are constructs that possess all of the behavioral features and responses of a sentient human being, yet are not conscious. P-zombies are intimately linked to the hard problem of consciousness and have been invoked as arguments against physicalist approaches. But what if we were to invert the characteristics of p-zombies? Such an inverse (i-) zombie would possess all of the behavioral features and responses of an insensate being yet would nonetheless be conscious. While p-zombies are logically possible but naturally improbable, an approximation of i-zombies actually exists: individuals experiencing what is referred to as “anesthesia awareness.” Patients under general anesthesia may be intubated (preventing speech), paralyzed (preventing movement), and narcotized (minimizing response to nociceptive stimuli). Thus, they appear—and typically are—unconscious. In 1-2 cases/1000, however, patients may be aware of intraoperative events, sometimes without any objective indices. Furthermore, a much higher percentage of patients (22% in a recent study) may have the subjective experience of dreaming during general anesthesia. P-zombies confront us with the hard problem of consciousness—how do we explain the presence of qualia? I-zombies present a more practical problem—how do we detect the presence of qualia? The current investigation compares p-zombies to i-zombies and explores the “hard problem” of unconsciousness with a focus on anesthesia awareness.

It is widely held that there is a problem of talking about or otherwise representing things that not exist. But what exactly is this problem? This paper presents a formulation of the problem in terms of the conflict between the fact that there are truths about non-existent things and the fact that truths must be answerable to reality, how things are. Given this, the problem of singular negative existential statements is no longer the central or most difficult aspect of the problem of non-existence, despite what some philosophers say.

As I type these words, cognitive systems in my brain engage in visual and auditory information processing. This processing is accompanied by subjective states of consciousness, such as the auditory experience of hearing the tap-tap-tap of the keyboard and the visual experience of seeing the letters appear on the screen. How does the brain's activity generate such experiences? Why should it be accompanied by conscious experience in the first place? This is the hard problem of consciousness.

If we assume that the operation of each sense modality constitutes a different experience – a visual experience, an auditory experience, etc – we are faced with the problem of how those distinct experiences come together to form a unified perceptual encounter with the world. Michael Tye has recently argued that the best way to get around this problem is to deny altogether that there are such things as purely visual (and so forth) experiences. Here I aim to show not simply that Tye’s proposed solution fails, but that its failure is highly instructive because it allows us to see that the transparency thesis, which lies at the heart of the case against qualia, and of most representationalist theories of experience, is more problematic than is often supposed.

From now on I will assume that it is possible in principle for there to be cases of spectrum inversion in which the invertees are equally good perceivers of the colors. What I want to show next is that while allowing this possibility is incompatible with standard representationalism, it requires acceptance of a different version of representationalism. Consider the standard way of describing a case of spectrum inversion. Returning to Jack and Jill, we say that red things look to Jack the way green things look to Jill, blue things look to Jack the way yellow things look to Jill, and so on. Of course, we might also express this by saying that the phenomenal character of Jack’s experience of red things is like the phenomenal character of Jill’s experience of green things, and so on. Or by saying that “what it is like” for Jack to see red things is “what it is like” for Jill to see green things, and so on. But “phenomenal character” is philosophical jargon, and “what it is like” is on its way to being that. We need to be able cash these locutions in terms that we are sure we understand. And I think that the best way of doing that is in terms of how things look. Now the sense in which red things look different to Jack and Jill cannot be that they look to have different colors in the epistemic sense. We can suppose that both perceive red things as being red, and therefore that to both red things look red in the epistemic sense. Nor can it be the comparative sense – to each, we can suppose, red things look like standard red things under standard conditions. The remaining sense of “looks” is supposed to be the phenomenal sense. Now those who employ this notion typically speak of things as looking red, blue, yellow, etc., in the phenomenal sense. But if Jack and Jill are both accurate perceivers of the colors of things, it can’t be that the difference in how things look to them is a difference in what colors things look to them, even if “looks” is used in the phenomenal sense..