Online research in philosophy

Our various theories and conceptions of colours are influenced by the two main perspectives which we have on them. On the one hand, colours are directly given to us, in our conscious perceptual experiences, as features of objects in our environment. As part of these experiences, the colours instantiated by the objects are presented as having certain qualitative and certain categorial properties. Among the sensorily presented qualitative features of colours are, first of all, their various internal similarities and differences. Thus, two colours may be experienced as being closer to each other in their hue, their saturation or their brightness than a third colour. Their qualitative features also include the property of being unique (or elemental) or, alternatively, the property of being binary (or compound). While unique shades of hue are experienced as not involving any other colour hues, binary shades of hue are experienced as being qualitatively composed out of the former. The property of being instantiated independently of our particular experiences and the property of being instantiated by some actually existing objects are some of the categorical features1, which we non-sensorily experience colour instances as having. That is, the colours which we perceive are given to us as mind-independent properties of real objects. Another relevant aspect - though probably more controversial - may perhaps be that we experience colour instances as determining our perceptions of them. The idea is that, while seeing the colours of objects, we are aware of the fact that, if the colours would have been different, our experiences of them would have been correspondingly different as well (cf. Author (2010a)). The categorial features are the same for all perceived colours instances that we perceive. The qualitative features, of course, differ relative to which colour we experience. The non-sensory presentation of the categorical features of colour instances and the sensory presentation of the qualitative features of the colours involved contribute to the subjective character of the relevant colour experiences — to what they are subjectively like..

The literature on the Knowledge Argument exhibits considerable confusion about the precise nature of the argument. I contend that a clarification of the essence of self-presenting properties provides an explanation of this confusion such that the confusion itself is evidence for dualism. I also claim that Mary gains six different sorts of knowledge after gaining sight, and I show how this claim provides a response to a physicalist undercutting defeater for the Knowledge Argument. I try to show that this defeater is inadequate due to its failure to capture the epistemic richness of what happens to Mary. Finally, I indicate how my enriched version of the Knowledge Argument provides grounds for rejecting those varieties of physicalism that eschew a depiction of phenomenal propertiesas intrinsic attributes a subject exemplifies in favor of a view that treats them as functional roles a subject realizes.

Frank Jackson first presented the Knowledge Argument (henceforth KA) in "Epiphenomenal Qualia" 1982). The KA is an argument against physicalism, the doctrine that (very roughly put) everything is physical. The general thrust of the KA is that physicalism errs by misconstruing or denying the existence of the subjective features of experience. Physicalists have given numerous responses, and the debate continues about whether the KA ultimately succeeds in refuting any or all forms of physicalism. Jackson himself has recently.

Frank Jackson's knowledge argument against physicalism has caused an extensive debate. In this paper, I sketch and examine a new argument against Jackson's view, an argument which appears to retain more of physicalism than other replies to Jackson. this argument draws strength from a causal theory of knowledge, and hold that there is no knowledge of epiphenomenal qualia, hence that Jackson's main conclusions from the thought experiment are incorrect. There are still problems with this argument, however, so the question remains how much of the mental that can be accounted for in physicalist terms.

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.

One of the main targets of Barry Stroud’s criticism in his recent book ‚The Quest for Reality. Subjectivism and the Metaphysics of Colour’ are eliminativist theories of colour which he regards as a version of the metaphysical project of the unmasking of colours (Stroud, 2000). According to this view, no physical objects have any of the colours we see them or believe them to have. However, although this error theory describes all our colour perceptions as illusory, and all our colour beliefs as false, it cannot deny that we actually perceive colours and that we do believe that physical objects are coloured. Therefore, it has to account for these psychological facts without relying on any assumptions about the colours of things. Thus, the central question for the unmasking project is whether it is possible to acknowledge someone’s perceiving a certain colour or having beliefs about the colours of things without holding that anything anywhere has any colour at all. Contrary to Stroud, this paper defends the view that we can acknowledge that people believe in colours without having ourselves to accept their existence.

I argue that Frank Jackson's knowledge argument cannot succeed in showing that qualia are epiphenomenal. The reason for this is that there is, given the structure of the argument, an irreconcilable tension between his support for the claim that qualia are non-physical and his conclusion that they are epiphenomenal. The source of the tension is that his argument for the non-physical character of qualia is plausible only on the assumption that they have causal efficacy, while his argument for the epiphenomenal character of qualia is plausible only on the assumption that they are non-physical. Since these two arguments cannot be combined coherently, the most Jackson's argument can establish is that qualia are non-physical.

Frank Jackson’s knowledge argument is a very influential piece of reasoning that seeks to show that colour experiences constitute an insoluble problem for science. This argument is based on a thought experiment concerning Mary. She is a vision scientist who has complete scientific knowledge of colours and colour vision but has never had colour experiences. According to Jackson, upon seeing coloured objects, Mary acquires new knowledge that escapes her complete scientific knowledge. He concludes that there are facts concerning colour experiences that scientific knowledge can neither describe nor explain. Specifically, these facts involve the occurrence of certain non-physical properties of experiences that he calls qualia. The present research considers whether a plausible formulation of the hypothesis that science can accommodate colour experiences is threatened by a version of the knowledge argument. The specific formulation of this problem has two motivations. Firstly, before investigating whether the knowledge argument raises a problem for the claim that science can account for colour experiences, we need a plausible formulation of this claim. I argue that the idea that science can accommodate colour experiences can be formulated as the modest reductionism hypothesis. Roughly speaking, this is the hypothesis that a science that can be explanatory interfaced with current physics of ordinary matter can account for conscious experiences. Secondly, an unintelligible premise figures in Jackson’s version the knowledge argument. Namely, it is assumed that Mary possesses a complete (future or possible) scientific knowledge. Nevertheless, the type of strategy involved in Jackson’s argument can be used to target modest reductionism. By considering contemporary psychophysics and neuroscience, I characterise Mary’s scientific knowledge. First, this characterisation is intelligible. In fact, it is elaborated on the basis of descriptions and explanations of colour experiences involved in current physics and neuroscience. Second, a supporter of modest reductionism can assume that the scientific knowledge ascribed to Mary might account for colour experiences. The main conclusion of the present research is that our version of the knowledge argument fails to threaten the modest reductionism hypothesis. In fact, I endorse what can be called the “two ways of thinking” reply to the knowledge argument. According to this response, the knowledge argument shows that there are different ways of thinking about colour experiences. One way of thinking is provided by scientific knowledge. The other way of thinking is provided by our ordinary conception of colour experiences. However, the existence of these two ways of thinking does not imply the existence of facts and properties that escape scientific knowledge. It might be the case that the ordinary way of thinking about colour experience concerns facts and properties described and explained by science. The principal conc

Physicalism about colour is the thesis that colours are identical with response-independent, physical properties of objects. I endorse the Argument from Structure against Physicalism about colour. The argument states that Physicalism cannot accommodate certain obvious facts about colour structure: for instance, that red is a unitary colour while purple is a binary colour, and that blue resembles purple more than green. I provide a detailed formulation of the argument. According to the most popular response to the argument, the Physicalist can accommodate colour structure by explaining it in terms of colour experience. I argue that this response fails. Along the way, I examine other interesting issues in the philosophy of colour and colour perception, for instance the relational structure of colour experience and the description theory of how colour names refer.

Frank Jackson’s knowledge argument (KA) aims to prove, by means of a thought experiment concerning the hypothetical scientist Mary, that conscious experiences have non-physical properties, called qualia. Mary has complete scientific knowledge of colours and colour vision without having had any colour experience. The central intuition in the KA is that, by seeing colours, Mary will learn what it is like to have colour experiences. Therefore, her scientific knowledge is incomplete, and conscious experiences have qualia. In this paper I consider an objection to the KA raised by Daniel Dennett. He maintains that the KA is vitiated by Jackson’s account of Mary’s scientific knowledge. While endorsing this criticism, I will defend the plausibility and relevance of the type of strategy involved in the KA by offering an account of Mary’s scientific knowledge. This account involves formulating a reasonable and not immediately false version of the physicalist thesis with regard to colour experiences. Whether this version of the KA is successful against this type of physicalism is not investigated here.