Naturalistic_Dualism

Filosoofia teadvusekäsitlusi Naturalistic dualism by David Chalmers (The Concious Mind: In Search of a Fundamental Theory, 1996) Audentese Ülikool Triin Kaljuvee-O'Brock PSM 13 1. 06.04 NATURALISTIC DUALISM The idea of “naturalistic” dualism is to respect natural science entirely, denying nothing that is known, rejecting only the classical mechanistic 19th-century view according to which nothing fundamentally exists but individual subatomic particles and their dynamic and kinematic properties. According to the naturalistic dualist, the foregoing objections to Cartesian and property dualism are at least tacitly based on the classical view, and can be circumvented if we abandon that view. Naturalistic dualism was inaugurated by W. Sellars in the 1950’s, although the idea did not catch on until thirty or forty years later. Sellars argued that the subjectively felt phenomenal qualities of sensations could not be identified with, otherwise reduced to, or even accommodated within the “punctiform” metaphysics afforded by classical particulate mechanics. He called such subjective qualitative properties “sensa”. But, rather than insisting that sensa are outside physical reality itself, Sellars contended that they will have a home within a suitably expanded physics, and so are part of nature after all. David Chalmers also calls his theory of consciousness “naturalistic dualism". He writes: "To capture the spirit of the view I advocate, I call it naturalistic dualism. It is naturalistic because it posits that everything is a consequence of a network of basic properties and laws, and because it is compatible with all the results of contemporary science. And as with naturalistic theories in other domains, this view allows that we can explain consciousness in terms of basic natural laws. . . . Some might find a certain irony in the name of the view, but what is most important is that it conveys the central message: to embrace dualism is not necessarily to embrace mystery." He concludes that consciousness cannot be explained by existing physical sciences. He thinks that consciousness cannot be explained the way the physical sciences explain everything else: by reducing the system to ever smaller parts. He is trying to find a "nonreductive" explanation of consciousness. In this article D. Chalmers draws out that the failure of logical supervenience directly implies that materialism is false: there are features of the world over and above the physical features. The basic argument for this goes as follows: 1. In our world, there are conscious experiences. 2. There is a logically possible world physically identical to ours, in which the positive facts about consciousness do not hold. 3. Therefore, facts about consciousness are further facts about our world, over and above the physical facts. 4. So materialism is false. Chalmers' argument basically goes back to the "zombie" question: if a physical copy of you is built by some futuristic machine, would that copy of you experience the same feelings you experience' Chalmers argues that physical identity is not enough. According to Chalmers zombies are not physical possibilities, but they are at the very least logical or conceptual possibilities. Chalmers says that his own theory of consciousness is a variant of "property dualism": there are no two substances (mental and physical), there is only one substance, but that substance has two separate sets of properties, one physical and one mental. Conscious experience is due to the mental properties. The physical sciences have studied only the physical properties. The physical sciences study macroscopic properties like "temperature" that are due to microscopic properties such as the physical properties of particles. Chalmers advocates a science that studies the "protophenomenal properties" of microscopic matter that can yield the macroscopic phenomenon of consciousness. I think that his parallel with electromagnetism is very interesting and descriptive. Electromagnetism in the 19th century could only be explained by creating a new set of fundamental laws. Similarly, consciousness cannot be explained by the physical laws of the known properties but requires a new set of "psychophysical" laws that deal with "protophenomenal properties". Consciousness supervenes naturally on the physical: the new "psychophysical" laws will explain this supervenience, they will explain how conscious experiences depend on physical processes. Although he views his theory as a variety of dualism, he also says that it could be a type of monism. What if the physical and phenomenal will turn out to be two different aspects of a single encompassing kind, in something like the way that matter and energy turn out to be two aspects of a single kind' But he rules out the possibility of a materialist monism and feels it must be something broader. In Objections from a posteriori necessity he argues that materialism must hold that consciousness is logically supervenient on the physical; that materialists cannot appeal to metaphysical supervenience as a way of avoiding the problems he raises with logical supervenience; and that therefore, materialism fails. This objection is accompanied by an appeal to Kripke’s Naming and Necessity (1980), which demonstrates the existence of necessary truths such as "Water is H2O" whose necessity is only knowable a posteriori. In the terms of these objectors, it is logically possible that water is not H2O, but it is not metaphysically possible. It is not unnatural to suppose that zombies might be logically possible but metaphysically impossible in a similar way. If so, this would arguably be enough to save materialism. In arguing against the materialist’s metaphysical identity maneuver, Chalmers makes use of a distinction between primary and secondary intensions. An intension is something like the meaning or reference of a concept. The primary intension of a concept picks out whatever object or substance that concept refers to in the possible world that one is in. This idea is easier understood with an example such as water. The concept WATER refers to the clear, tasteless, drinkable liquid which is found in rivers, lakes, and oceans. This primary intension does not explain what the chemical composition of the stuff in the oceans happens to be. If it turned out that there was XYZ in the ocean, then the term ‘water’ would refer to XYZ; likewise, if there was H2O in the oceans, ‘water’ would refer to H2O. So the primary intension can really just be thought of as picking out what Chalmers refers to as “watery stuff” in whatever possible world one is in; therefore, the primary intension of a concept is a priori. The secondary intension of a concept is not a priori; rather, its reference depends upon how our world is. The secondary intension is discovered by applying the primary intension of a concept in our world. For example, we discover that what we call ‘water’ actually has the chemical composition H2O, and this is its secondary intension. We can then apply the same reference across all possible worlds, so that in a world in which XYZ is found in the oceans, the term ‘water’ still only refers to H2O, not what’s in the oceans. Given that the primary intension of water (i.e., watery stuff) picks out H2O in our world, the concept WATER picks out H2O in all possible worlds according to its secondary intension. Once we understand this structure, we can determine the difference between logical (a priori) and metaphysical (a posteriori) necessity. A statement is logically necessary if it is true in all possible worlds when it is evaluated according to its primary intensions. Conversely, a statement is metaphysically necessary if it is true in all possible worlds when it is evaluated according to its secondary intensions. He ends his chapter about the objections from a posteriori necessity with another statement against materialism : "We can simply forget the semantics of these terms, and note that the relevant possible world clearly lacks something, whether or not we call it “consciousness.” The Kripkean considerations might tell us at best how this world and the relevant features should be appropriately described, but they have no effect on its possibility; and the mere possibility of such a world, no matter how it is described, is all the argument for dualism needs to succeed". Chalmers also argues against strong necessities, saying there is no reason to believe in them. In particular, he says that a) they cannot be supported by analogy with other a posteriori necessities; b) they involve a far more radical sort of a posteriori necessity than Kripke's, requiring a distinction between logical and metaphysical possibility at the level of worlds; c) they lead to an ad hoc proliferation of modalities, d) they raise deep questions of coherence, e) strong necessities will be brute and inexplicable, and (f) the only motivation to postulate such necessities is the desire to save materialism. In Cognitive limitations Chalmers attempts to answer the objection that facts about consciousness might bear a relationship to the physical supervenience base analogous to the relationship between undecidable truths and the formal systems in terms of which they are phrased. The objection is significant because if there were a convincing analogy, it would suggest that we simply might not be able to grasp the logical supervenience relation even if there is one. Here, however, as elsewhere, a weak grasp of formal systems compromises the quality of the reply offered in the text. Indeed, an objector need not even appeal to the raw limits of absolute decidability -- the limits of computational tractability would do fine. Chalmers appears to view human cognizers as ideally rational beings for whom at least some limitations of the real world are irrelevant. Chalmers attempts to back up his theory with arguments for dualism from Jackson and Kripke, but to fully examine both of these arguments in addition to Chalmers’ own would need to be addressed separately with additional supporting works brought into the discussion by Jackson and Kripke. In conclusion, I believe the author did a pretty poor job of defending his theory and used most of this chapter pointing out exceptions to the rule in hopes of creating his own new set of rules regarding body and mind relationship. Perhaps the creating of new rules to support personal theories is what philosophy is all about. Some of the concepts proposed are so over the limits of layman understanding that it would lead me to refer to something a wise man is credited with saying some 2500 years ago. "Those who know don’t talk, those who talk don’t know". This quote is credited to the philosopher Lao-Tzu and quoted from the book of the Tao te Ching. I don’t wish to undermine the author’s work or to stifle his attempts in creating a new theory, but it is my opinion that the field of philosophy has been so worked through ("My teachings are older than the world. How can you grasp their meaning'" Lao-Tzu) that I am skeptical if the modern scientific world can lend much to the discovery of completely new proven theories regarding consciousness.