Qualia
Under qualia (singular: the Quale, from Latin qualis " as is" ) or phenomenal consciousness refers to the subjective experiential content of a mental state. Understanding the Qualia is one of the central problems of philosophy of mind, as is often assumed that their existence can not be explained using the tools of neuroscience and cognitive science.
The first use of the term can be dated to the year 1866 and goes back to the American philosopher Charles S. Peirce, but in 1929 he was determined in accordance with the current philosophy of mind by CI Lewis in the book Mind and the World Order as " recognizable characters of the given, which can be recognized, and therefore a kind of universals ". A frequently encountered in the literature synonymous with the concept of qualia is the English term raw feels.
- 4.1 representational strategies
- 4.2 Qualiaeliminativismus
- 4.3 Nichtreduktionistische strategies
Definition
Under " qualia " of the subjective experiential content of mental states is understood. But it is precisely such a subjective element seems to defy any intersubjective definition. The philosopher Thomas Nagel has to determine the Qualia shaped the speech that it was " in a certain way feels " in a mental state to be ( what is it like). If a person about freezes, it has several consequences of the rule. In the person about different neural processes take place and the person will show a certain behavior. But that's not all: "It feels for the person on a certain way to " freeze. However, nail determination test shall not apply as a general definition. A determination of qualia by the phrase " feel a certain way " assumes that this phrase is already understood. Who but the talk of subjective experience levels does not make sense, which is also not understand the phrase. Ned Block commented on the problem of definition, therefore, as follows:
"You ask: What is it, what, have called qualitative states ' philosophers? And I answer, only half in jest: As Louis Armstrong said, when asked what jazz is. If you have to ask first, you'll never understand it "
The problems that occur in the determination of qualia have some philosophers such as Daniel Dennett, Patricia and Paul Churchland meant to deny the existence of qualia altogether and instead represented a Qualiaeliminativismus. For the majority of philosophers and scientists, however, the existence of a subjective experience content is undeniable. Ansgar Beckermann comments about:
"And if someone says he still does not know where the qualitative character derives about a judgment of taste, we can address this lack of understanding as follows: We give him a sip to drink wine, then let it suck a peppermint and then give him a sip of the same wine with the remark that what has changed now, this is the qualitative character of your judgment of taste ".
The riddle of qualia
Even if the explicit discussion of qualia only emerged in the 20th century, the problem of the case is already widely known for some time: even with René Descartes, John Locke and David Hume can be similar, if not also find further explained thoughts of this kind. Hume, for example, argued in his Treatise on Human Nature ( 1739 ):
"We can not form to ourselves a just idea of the taste of a pineapple, without having tasted it Actually. "
"We can form no idea of the taste of a pineapple without having them actually cost. "
Even Gottfried Wilhelm Leibniz formulated the qualia problem in a haunting thought experiment. Leibniz runs us through a giant model of the brain. Such a model will inform you of how stimuli are processed in a very complex manner in the brain, and finally by means of excitation forwarding in different parts of the body lead to a reaction (see stimulus-response model). But, according to Leibniz, anywhere we will discover consciousness in this model. A neuroscientific description will therefore let's talk about the consciousness completely in the dark. In Leibniz's thought experiment, one can easily discover the qualia problem. Because to what you can not discover in the brain model, include obviously the Qualia. The model may enlighten us about how a light wave strikes the retina, are thereby led signals to the brain and there were finally processed. However, it will not enlighten us by Leibniz's view on why the person has a Rotwahrnehmung.
Another early formulation of the qualia problem goes back to the physiologist Emil du Bois- Reymond and his Ignorabimusrede. In his 1872 held at the meeting of natural scientists in Leipzig lecture about the limits of knowledge of nature du Bois- Reymond explains the question of consciousness to a fundamentally inexplicable riddle of the universe:
" What conceivable connection between certain movements of certain atoms in my brain on the one hand, on the other hand, the original for me, not definable on, not wegzuleugnenden facts ' I feel pain, I feel like; I taste sweet, smell the scent of roses, hear sound of the organ, see Roth ... ' "
Du Bois -Reymond want here on the experience levels, the qualia addition. By emphasizing the lack of epistemic connection that exists between the brain and qualia Bois- Reymond has also anticipated the explanatory gap argument, as it has been formulated by Joseph Levine (see below).
The current debate about qualia is based primarily on the essay What is it like to be a bat? ("How does it feel to be a bat ?") Of the philosopher Thomas Nagel. Nail essay coincided with a period in which the philosophy of mind was influenced predominantly by the reductionist developments in neuroscience and cognitive science. He now argues that science could not explain the phenomenon of experiencing. Finally, the sciences are fixed in their method to an external perspective, in which the internal perspective of the experience did not leave grasp. Nagel tries to illustrate his position with a famous example. He encourages you to imagine a bat. Now we can, argues Nagel, in so strange creatures indeed perform many neuroscientific and ethological experiments, while also something about the cognitive abilities of a bat to find out. As it is, however, feel for the bat to locate about an object by means of echolocation, remain closed to us. Nagel concludes from this example that the subjective perspective of qualia is not to be discovered through the objective perspective of the natural sciences.
Qualia arguments
In addition to the qualia problem generally formulated specific arguments have been formulated on the basis of qualia again. Some have the goal to determine the issue further. Others want to derive from it consequences, such as a critique of materialism.
The Mary thought experiment
Main article: Mary ( thought experiment )
The most famous anti- materialism qualia -based argument comes from the Australian philosopher Frank Cameron Jackson. In his essay What Mary did not know ("What Mary did not know " ) Jackson formulated the thought experiment of the super scientist Mary. Mary is a specialized color vision physiologist who is trapped in a black-and- white lab since birth and has never seen colors. She knows all the physical facts about seeing colors, but do not know how colors look. Jackson's argument against materialism is now quite short: Mary knows all the physical facts about seeing colors - but she does not know all the facts about seeing colors. He concludes that there are non-physical facts and materialism is wrong.
Against this argument various materialist responses have been put forward. David Lewis argues that Mary gets to know of any new facts when she first sees colors. Rather, it would only acquire a new skill - the ability to distinguish colors visually. Michael Tye also argues that Mary would know all the facts about seeing colors before their liberation. Mary would only get to know a fact already known in a new way. Daniel Dennett eventually even declared that it does is nothing new for Mary when she perceives color for the first time visually. Such a comprehensive physiological knowledge about seeing of colors - she knows everything - would provide them with all information.
The explanatory gap argument
In contrast to the Mary thought experiment the explanatory gap argument, developed primarily by Joseph Levine is not directed against materialism. On the contrary, Levine emphasizes that this case concerns an epistemological and metaphysical no argument. It can therefore only show that we have not understood something basic, but make no statement about the ontological status of qualia. Specifically wants to show that we have not understood how qualia can arise from neural or functional states Levine. To achieve this goal, attempts to formulate reductive explanations Levine standards. Then he argues that in attempts to explain qualia reduction, these standards are undermined.
How now look reductive explanations? Levine discusses the classic example of water and H2O. The reduction of water seem to pose no fundamental problems. According to Levine, the reason is that we can explain all the properties of water at the level of chemical and physical theories. We can thus explain why water is transparent, liquid or odorless. If not possible, so not a complete reduction of water would be managed. This is exactly, argues Levine, but in mental states the case. We can not explain why mental states such as pain or perception states have the property to be experienced. Consequently, in mental states remains an explanatory gap (explanatory gap) exist and a reduction is not possible.
Missing and inverted qualia
Even with the thought experiments of the missing and inverted qualia the claim is connected to demonstrate the mystery of qualia. The thought experiments are based on the fact that the transition from neural states to experience states is by no means obvious. An example (see chart): A neural state A is accompanied by a Rotwahrnehmung, a state B with a blue perception. Now the thought experiment of the inverted qualia says that it is also conceivable that this is exactly reversed expire: the same neural state A could also be accompanied by a blue perception, the same neural state B with a Rotwahrnehmung.
The thought experiment of the lack of qualia asserts, moreover, that it is even conceivable that a neural state face no qualia. The idea of missing qualia therefore boils down to the hypothesis of " philosophical zombies " addition: It is conceivable that beings have the same neural states as other people and are thus no different in the behavior of these. Yet they had in relation to the considered neural state, no experience, the neuronal states correlated so no qualia.
Regarding the motives for these thought experiments, one must differentiate between two different readings - an epistemological and a metaphysical - differ. Philosophers who prefer the epistemological interpretation want to show with the thought experiments that can not yet be qualia reduce to neural states. They argue that the conceivability of kicking apart of neural state and Qualia show that we have not understood the connection between the two. Again, the water sample is often sought: If water has been successfully reduced to H2O, it is no longer conceivable that H2O vorliege without at the same time vorliege water. This is simply not be imagined, because the presence of water can be derived under the conditions of the chemistry and physics from the presence of H2O. Only could therefore be said that water had been reduced to H2O. One equivalent of the chemical-physical theory behind this successful reduction based on, but is lacking in the field of neural and mental phenomena.
The metaphysical interpretation of the inverted and missing qualia, however, has even farther-reaching consequences. Representatives of this line of argument to prove the thought experiments that qualia are not identical with properties of neural states. You have ultimately a refutation of materialism in mind. Argue, as follows: If X and Y are identical, then it is not possible that X is present, without at the same time Y is present. This one could easily be illustrated with an example: When Augustus is identical with Octavian, then it is not possible that Augustus occurs without Octavian, they are ultimately a person. Now the representative of the metaphysical reading further argue that thought experiments have shown that it is possible that neuronal states occur without qualia. So qualia could not be identical with properties of neural states. Such an argument must of course be the objection like that thought experiments do not show that it is possible that neuronal states occur without qualia. They only show that this is conceivable. Representative of the metaphysical reading retort that a priori conceivability always also implies possibility in principle. Influential arguments to show this, Saul Kripke has formulated. A recent elaboration offer Frank Cameron Jackson and David Chalmers. Of fundamental importance is the so-called Two-dimensional semantics.
- Alex Byrne: Inverted Qualia. In: Edward N. Zalta (ed.) Stanford Encyclopedia of Philosophy
Explanatory models
Representational strategies
Representational strategies are enjoying great popularity among materialist philosophers, variants are represented approximately by Thomas Metzinger, Fred Dretske and Michael Tye. One goal of such positions is attributed to qualia representational states. If one stands out with some kind of needle in the finger, the stitch is represented by neural states. The experience is now to be nothing else than the mode of representation. Now is often argued that it is not plausible that representations are already a sufficient condition for experience. On the one hand have simple systems, such as a thermostat, also representational states, on the other hand there seems to be unconscious representations in humans. An example from the neuropsychology include the cases of cortical blindness ( blindsight ), in which people have perceptions, but which it does not register cognitively or qualitatively. Some philosophers, such as David Rosenthal, therefore, represented as a Metarepräsentationalismus. According to him, qualitative states can be realized by representations of representations.
But now all representational strategies are confronted with the objection that even they can not solve the qualia problem. Because you can also ask for representational states, why they should be because accompanied by experience. Were not all representations without qualia conceivable?
Some materialist philosophers respond to this problem by claiming that they did not have to explain how material - lead states to experience - as representational. For example, David Papineau has argued that one must simply accept the identity of an experience state with a material condition to be able to require no explanation for this identity. The question " Why X and Y are identical to each other? " Simply was a bad question and therefore the riddle of qualia legally as a pseudo-problem. Representatives of the thesis that qualia are puzzling answer to this objection is that they do not also provide the above question. They explain that they want to know rather how it is possible that the subjective experience with a physical process is identical and they claim that this question is not clear, as long as no reduction of qualia has succeeded.
While Papineau also holds the second question to be unjustified, recognize other materialist philosophers here in the existence of a riddle. Still others turn to the position of Qualiaeliminativismus or departing from the scope of materialistic theories.
Qualiaeliminativismus
A particularly radical proposal to solve the problem qualia does the American philosopher Daniel Dennett: He claims that it did not exist in reality Qualia. Such a position seems to many philosophers as totally implausible, if not incomprehensible. "Of course we have subjective experiences ," she explained, " nothing could be more secure than this. " Dennett, however, claimed that such statements only the expression of outdated metaphysical intuitions are that still feed off of metaphysics in the tradition of René Descartes. In reality was " qualia " is a completely contradictory term which could be abolished in the course of scientific progress, about as, as has been found that the term " witch " or " phlogiston " in reality nothing corresponds. Dennett makes now because ( ineffable, private, intrinsic) to attack the various ideas that have been Qualia, and says that these properties can be the Qualia not awarded. It remains, according to Dennett left an empty phrase sleeve, which could be abolished without loss. Although most philosophers reject Dennett's argument, but it has triggered a wide debate. Dennett's position is supported by about Patricia Churchland and Paul Churchland and other eliminative materialists.
Nichtreduktionistische strategies
As reductionist and eliminativistische strategies are facing enormous problems, positions are attractive to explain that it was not necessary to take such tests. The classic nichtreduktionistische and nichteliminativistische position of dualism. If qualia are no material entities, you need neither be reduced to neural states nor to worry if such a reduction attempts fail. Against a dualistic approach is, however, traditionally argued that he could no longer make the interaction of qualia with the material world for granted. Finally, every physical event has a sufficient physical cause. So there would remain no room for moral causes. But it seems to be very implausible to claim that about a sensation of pain not the cause of a physical event - could be - namely the person's behavior. A particularly succinct formulation of these problems provides the so-called Bieri trilemma.
Another nichtreduktionistische and nichteliminativistische position is the term pluralism, as it has been formulated as Nelson Goodman. He claims that there are different ways of describing, in addition to other with equal rights and yet are not reducible to each other. So the pain when you touch a hot stove and the neural activity in the brain of the person concerned are logically equivalent, almost as different sides of the same coin.
An even further generalization is a form of panpsychism, according to which each state of an arbitrary (not necessarily biological ) physical system corresponds to a quale or a set of qualia, but not necessarily a dualism in the sense of " soulfulness " of things (as in the classic panpsychism ) must be assumed. This approach has the advantage that it can be composed rather of " elementary qualia " and thus reversed also reduce to elementary processes no qualitative " leaps " in the transition from inanimate takes to living matter, but the complex human consciousness, as well as the physical appearance of the people can be recycled as many-particle system in an elementary physical processes. In this direction, arguing about David Chalmers. However, from a scientific point of view it is unsatisfactory because no experiment is known to prove the existence of these elementary qualia or would refute.
If the problem of qualia solve?
Given the extent of the qualia problem and the disunity of the different proposals voices are heard over and over again that keep the qualia problem can not be solved. Such a position is mainly represented by philosophers, on the one hand want to maintain the materialism, and on the other hand still hold reductionist and eliminativistische strategies for implausible. Thomas Nagel draws about considering the possibility that today's science is just not far enough to solve the qualia problem. Rather, in need of a new scientific revolution, before an answer to this riddle can be found. As an analogy is offered by the state before and after the Copernican theory. Some astronomical phenomena were within the geocentric just can not explain it required a fundamental change in scientific theories. Maybe a solution of qualia problem only in the future by new and fundamental insights of neuroscience and cognitive sciences is possible.
The British philosopher Colin McGinn even goes a step further. He claims that the qualia problem for humanity is generally not solvable. People have developed a cognitive apparatus in the course of evolution, which is not suitable to solve all problems. Rather, it is plausible that human cognition are set fundamental limits and that we have reached one of these barriers to the Qualia.
Advanced Topics
- For the wider context of debates about qualia see philosophy of mind, consciousness and mental causation.
- For the epistemological background of the debates explicability Qualia see reductionism.
- For the ontological implications of the qualia debate, see Dualism (ontology ) and physicalism.