A philosophical zombie (or " p-zombie ") is a being in a thought experiment in the philosophy of mind that is physically identical to a normal human being but does not have conscious experience .
92-469: For example, if a philosophical zombie were poked with a sharp object, it would not feel any pain, but it would react exactly the way any conscious human would. Philosophical zombie arguments are used against forms of physicalism and in defense of the hard problem of consciousness , which is the problem of accounting in physical terms for subjective, intrinsic, first-person, what-it's-like-ness experiences. Proponents of philosophical zombie arguments, such as
184-448: A necessary but not sufficient condition for physicalism. Additional objections have been raised to the above definitions provided for supervenience physicalism: one could imagine an alternative world that differs only by the presence of a single ammonium molecule (or physical property), and yet based on (1), such a world might be completely different in terms of its distribution of mental properties. Furthermore, there are disputes about
276-494: A "via negativa" characterization of the physical. The gist of the via negativa strategy is to understand the physical in terms of what it is not: the mental. In other words, the via negativa strategy understands the physical as "the non-mental". An objection to the via negativa conception of the physical is that (like the object-based conception) it lacks the resources to distinguish neutral monism (or panprotopsychism) from physicalism. Further, Restrepo argues that this conception of
368-426: A brain structurally identical to Davidson's and will thus presumably behave exactly like Davidson. He will return to Davidson's office and write the same essays he would have written, recognize all of his friends and family, and so forth. John Searle 's Chinese room argument deals with the nature of artificial intelligence: it imagines a room in which a conversation is held by means of written Chinese characters that
460-511: A conscious system, yet not be conscious. Physicalism In philosophy , physicalism is the view that "everything is physical ", that there is "nothing over and above" the physical, or that everything supervenes on the physical. It is opposed to idealism , according to which the world arises from mind. Physicalism is a form of ontological monism —a "one substance " view of the nature of reality , unlike "two-substance" ( mind–body dualism ) or "many-substance" ( pluralism ) views. Both
552-403: A different challenge: the "blockers problem". Imagine a world w 1 where the relation between the physical and non-physical properties at this world is slightly weaker than metaphysical necessitation, such that a certain kind of non-physical intervener—"a blocker"—could, were it to exist at w 1 , prevent the non-physical properties in w 1 from being instantiated by the instantiation of
644-429: A false belief. Lynch thinks denying the possibility of zombies is more reasonable than questioning our own consciousness. Furthermore, when the concept of self is deemed to correspond to physical reality alone (reductive physicalism), philosophical zombies are denied by definition. When a distinction is made in one's mind between a hypothetical zombie and oneself (assumed not to be a zombie), the hypothetical zombie, being
736-419: A long time, but I am quite used to it, now that I know that there is no alternative short of 'substance dualism'... Real physicalism, realistic physicalism, entails panpsychism, and whatever problems are raised by this fact are problems a real physicalist must face. Christian List argues that Benj Hellie's vertiginous question , i.e. why a given individual exists as that individual and not as someone else, and
828-444: A lot against there being such radical heterogeneity at the very bottom of things. In fact (to disagree with my earlier self) it is hard to see why this view would not count as a form of dualism... So now I can say that physicalism, i.e. real physicalism, entails panexperientialism or panpsychism. All physical stuff is energy, in one form or another, and all energy, I trow, is an experience-involving phenomenon. This sounded crazy to me for
920-413: A monistic framework. According to a 2020 survey, physicalism is the majority view among philosophers, but there also remains significant opposition to physicalism. Outside of philosophy, physicalism can also refer to the preference or viewpoint that physics should be considered the best and only way to render truth about the world or reality. The word "physicalism" was introduced into philosophy in
1012-446: A normal human being but lacking conscious experiences is therefore not logically possible according to the behaviorist, so an appeal to the logical possibility of a p-zombie furnishes an argument that behaviorism is false. Proponents of zombie arguments generally accept that p-zombies are not physically possible , while opponents necessarily deny that they are metaphysically or, in some cases, even logically possible. The unifying idea of
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#17328596000901104-533: A priori from PTI and a non-deferential grasp of the concepts "water" and "earth" et cetera . If this is correct, then we should (arguably) conclude that conceivability does not entail metaphysical possibility, and P2) of the conceivability argument against physicalism is false. Galen Strawson 's realistic physicalism or realistic monism entails panpsychism – or at least micropsychism . Strawson argues that "many—perhaps most—of those who call themselves physicalists or materialists [are mistakenly] committed to
1196-402: A priori physicalism and to physicalism in general is the "conceivability argument", or zombie argument . At a rough approximation, the conceivability argument runs as follows: P1 ) PTI and not Q (where "Q" stands for the conjunction of all truths about consciousness, or some "generic" truth about someone being "phenomenally" conscious [i.e., there is "something it is like" to be a person x] )
1288-438: A priori physicalists hold that PTI → N is a priori, they are committed to denying P1) of the conceivability argument. The a priori physicalist, then, must argue that PTI and not Q, on ideal rational reflection, is incoherent or contradictory . A posteriori physicalists, on the other hand, generally accept P1) but deny P2)--the move from "conceivability to metaphysical possibility". Some a posteriori physicalists think that unlike
1380-418: A reason to reject his principle. Frank Jackson 's knowledge argument is based around a hypothetical scientist, Mary, who is forced to view the world through a black-and-white television screen in a black and white room. Mary is a brilliant scientist who knows everything about the neurobiology of vision. Even though she knows everything about color and its perception (e.g. what combination of wavelengths makes
1472-535: A subset of the concept of oneself, must entail a deficit in observables (cognitive systems), a "seductive error" contradicting the original definition of a zombie. Thomas Metzinger dismisses the zombie argument as no longer relevant to the consciousness community, calling it a weak argument that covertly relies on the difficulty in defining "consciousness" and an "ill-defined folk psychological umbrella term". According to verificationism , for words to have meaning, their use must be open to public verification. Since it
1564-488: A world at which physicalism is true. Daniel Stoljar objects to this response to the blockers problem on the basis that since the non-physical properties of w 1 aren't instantiated at a world in which there is a blocker, they are not positive properties in Chalmers's sense, and so (3) will count w 1 as a world at which physicalism is true after all. A further problem for supervenience-based formulations of physicalism
1656-448: A world in which there are only physical properties; if physicalism is true at any world it is true at this one. But one can conceive physical duplicates of such a world that are not also duplicates simpliciter of it: worlds that have the same physical properties as our imagined one, but with some additional property or properties. A world might contain " epiphenomenal ectoplasm ", some additional pure experience that does not interact with
1748-512: Is epistemically —as a problem of causal explanation, rather than as a problem of logical or metaphysical possibility. The " explanatory gap "—also called the " hard problem of consciousness "—is the claim that (to date) no one has provided a convincing causal explanation of how and why we are conscious. It is a manifestation of the very same gap that (to date) no one has provided a convincing causal explanation of how and why we are not zombies. The philosophical zombie argument can also be seen through
1840-404: Is true at a possible world w if and only if any world that is a physical duplicate of w is also a duplicate of w simpliciter . Applied to the actual world (our world), (1) is the claim that physicalism is true at the actual world if and only if at every possible world in which the physical properties and laws of the actual world are instantiated, the non-physical (in the ordinary sense of
1932-487: Is type physicalism , or mind-body identity theory. Type physicalism asserts that "for every actually instantiated property F, there is some physical property G such that F=G". Unlike token physicalism, type physicalism entails supervenience physicalism. Another common argument against type physicalism is multiple realizability , the possibility that a psychological process (say) could be instantiated by many different neurological processes (even non-neurological processes, in
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#17328596000902024-411: Is a minimal physical duplicate of w is a duplicate of w simpliciter . Applied in the same way, (2) is the claim that physicalism is true at a possible world w if and only if any world that is a physical duplicate of w (without any further changes) is a duplicate of w without qualification. This allows a world in which there are only physical properties to be counted as one at which physicalism
2116-466: Is a property which metaphysically (or logically) supervenes on the sort of property required by a complete account of the intrinsic nature of paradigmatic physical objects and their constituents". Physicalists have traditionally opted for a "theory-based" characterization of the physical either in terms of current physics or a future (ideal) physics. These two theory-based conceptions of the physical represent both horns of Hempel's dilemma (named after
2208-448: Is assumed that we can talk about our qualia, the existence of zombies is impossible. Artificial intelligence researcher Marvin Minsky saw the argument as circular. The proposition of the possibility of something physically identical to a human but without subjective experience assumes that the physical characteristics of humans are not what produces those experiences, which is exactly what
2300-440: Is based on the requirement that one theory (mental or physical) be logically derivable from a second. The combination of reductionism and physicalism is usually called reductive physicalism in the philosophy of mind. The opposite view is non-reductive physicalism. Reductive physicalism is the view that mental states are both nothing over and above physical states and reducible to physical states. One version of reductive physicalism
2392-441: Is conceivable (i.e., it is not knowable a priori that PTI and not Q is false). P2 ) If PTI and not Q is conceivable, then PTI and not Q is metaphysically possible. P3 ) If PTI and not Q is metaphysically possible then physicalism is false. C ) Physicalism is false. Here proposition P3 is a direct application of the supervenience of consciousness, and hence of any supervenience-based version of physicalism: If PTI and not Q
2484-440: Is enough to refute physicalism. Such arguments have been criticized by many philosophers. Some physicalists, such as Daniel Dennett , argue that philosophical zombies are logically incoherent and thus impossible, or that all humans are philosophical zombies; others, such as Christopher Hill , argue that philosophical zombies are coherent but metaphysically impossible. Philosophical zombies are associated with David Chalmers, but it
2576-426: Is logically possible is also, in the sense relevant here, metaphysically possible. Another response is the denial of the idea that qualia and related phenomenal notions of the mind are in the first place coherent concepts. Daniel Dennett and others argue that while consciousness and subjective experience exist in some sense, they are not as the zombie argument proponent claims. The experience of pain, for example,
2668-401: Is metaphysically possible, which is all the argument requires. Chalmers writes: "Zombies are probably not naturally possible: they probably cannot exist in our world, with its laws of nature." The outline structure of Chalmers's version of the zombie argument is as follows: The above is a strong formulation of the zombie argument. There are other formulations of zombie-type arguments that follow
2760-479: Is non-mentally-and-non-biologically identifiable as one of the things that interact causally with certain particles (coincident with the pineal gland). The Platonic number eight is non-mentally-and-non-biologically identifiable as the number of planets orbiting the Sun". Adopting a supervenience -based account of the physical, the definition of physicalism as "all properties are physical" can be reduced to: (1) Physicalism
2852-491: Is non-physical. Therefore, consciousness is non-physical. Galen Strawson argues that it is not possible to establish the conceivability of zombies, so the argument, lacking its first premise, can never get going. Chalmers has argued that zombies are conceivable, saying, "it certainly seems that a coherent situation is described; I can discern no contradiction in the description." Many physicalist philosophers have argued that this scenario eliminates itself by its description ;
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2944-401: Is not reliable here. Yablo says he is "braced for the information that is going to make zombies inconceivable, even though I have no real idea what form the information is going to take." The zombie argument is difficult to assess because it brings to light fundamental disagreements about the method and scope of philosophy itself and the nature and abilities of conceptual analysis. Proponents of
3036-516: Is not something that can be stripped off a person's mental life without bringing about any behavioral or physiological differences. Dennett believes that consciousness is a complex series of functions and ideas. If we all can have these experiences the idea of the p-zombie is meaningless. Dennett argues that "when philosophers claim that zombies are conceivable, they invariably underestimate the task of conception (or imagination), and end up imagining something that violates their own definition". He coined
3128-491: Is one of the relevant facts about our world for determining whether a possible zombie world is accessible from our world. Therefore, asking whether zombies are metaphysically possible in our world is equivalent to asking whether physicalism is true in our world. Stephen Yablo 's (1998) response is to provide an error theory to account for the intuition that zombies are possible. Notions of what counts as physical and as physically possible change over time so conceptual analysis
3220-433: Is one that "if instantiated in a world W, is also instantiated by the corresponding individual in all worlds that contain W as a proper part." Following this suggestion, we can then formulate physicalism as follows: (3) Physicalism is true at a possible world w if and only if any world that is a physical duplicate of w is a positive duplicate of w . (3) seems able to handle both the epiphenomenal ectoplasm problem and
3312-471: Is physical if and only if it either is the sort of property that physical theory tells us about or else is a property which metaphysically (or logically) supervenes on the sort of property that physical theory tells us about". Likewise, the object-based conception claims that "a property is physical if and only if: it either is the sort of property required by a complete account of the intrinsic nature of paradigmatic physical objects and their constituents or else
3404-445: Is physical, and that everything physical is constituted out of physical ultimates, and that experience is part of concrete reality, it seems the only reasonable position, more than just an 'inference to the best explanation'... Micropsychism is not yet panpsychism, for as things stand realistic physicalists can conjecture that only some types of ultimates are intrinsically experiential. But they must allow that panpsychism may be true, and
3496-420: Is possible they exist, so dualism is false. Given the symmetry between the zombie and zoombie arguments, we cannot arbitrate the physicalism/dualism question a priori . Similarly, Gualtiero Piccinini argues that the zombie conceivability argument is circular. Piccinini questions whether the possible worlds where zombies exist are accessible from our world. If physicalism is true in our world, then physicalism
3588-416: Is possible, there is some possible world where it is true. This world differs from [the relevant indexing on] our world, where PTIQ is true. But the other world is a minimal physical duplicate of our world, because PT is true there. So there is a possible world which is a minimal physical duplicate of our world, but not a full duplicate; this contradicts the definition of physicalism that we saw above. Since
3680-434: Is some physical particular y such that x = y". It is intended to capture the idea of "physical mechanisms". Token physicalism is compatible with property dualism , in which all substances are "physical", but physical objects may have mental properties as well as physical properties. Token physicalism is not however equivalent to supervenience physicalism. First, token physicalism does not imply supervenience physicalism because
3772-419: Is sufficient for the consequent to be knowable a priori. An "a posteriori physicalist", on the other hand, will reject the claim that PTI → N is knowable a priori. Rather, they would hold that the inference from PTI to N is justified by metaphysical considerations that in turn can be derived from experience. So the claim then is that "PTI and not N" is metaphysically impossible. One commonly issued challenge to
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3864-437: Is the so-called "necessary beings problem". A necessary being in this context is a non-physical being who exists in all possible worlds (for example, what theists call God ). A necessary being is compatible with all the definitions provided, because it is supervenient on everything; yet it is usually taken to contradict the notion that everything is physical. So any supervenience-based formulation of physicalism will at best state
3956-506: Is therefore compatible with multiple realizability . From the notion of supervenience, it can be seen that, assuming that mental, social, and biological properties supervene on physical properties, two hypothetical worlds cannot be identical in their physical properties but differ in their mental, social or biological properties. Two common approaches to defining "physicalism" are the theory-based and object-based approaches. The theory-based conception of physicalism proposes that "a property
4048-409: Is true, since worlds in which there is some extra stuff are not "minimal" physical duplicates of such a world, nor are they minimal physical duplicates of worlds that contain some non-physical properties that are metaphysically necessitated by the physical. But while (2) solves the problem of worlds at which there is some extra stuff (sometimes called the "epiphenomenal ectoplasm problem" ), it faces
4140-487: Is true. A natural question for physicalists, then, is whether the truth of physicalism is deducible a priori from the nature of the physical world (i.e., the inference is justified independently of experience, even though the nature of the physical world can itself only be determined through experience) or can only be deduced a posteriori (i.e., the justification of the inference itself is dependent upon experience). So-called "a priori physicalists" hold that from knowledge of
4232-467: The conjunction of all physical truths, a totality or that's-all truth (to rule out non-physical epiphenomena, and enforce the closure of the physical world), and some primitive indexical truths such as "I am A" and "now is B", the truth of physicalism is knowable a priori. Let "P" stand for the conjunction of all physical truths and laws, "T" for a that's-all truth, "I" for the indexical "centering" truths, and "N" for any [presumably non-physical] truth at
4324-430: The 1930s by Otto Neurath and Rudolf Carnap . The use of "physical" in physicalism is a philosophical concept and can be distinguished from alternative definitions found in the literature (e.g., Karl Popper defined a physical proposition as one that can at least in theory be denied by observation ). A "physical property", in this context, may be a metaphysical or logical combination of properties which are physical in
4416-471: The 1970s by Thomas Nagel (1970; 1974) and Robert Kirk (1974), but the general argument was most famously developed in detail by David Chalmers in The Conscious Mind (1996). According to Chalmers, one can coherently conceive of an entire zombie world, a world physically indistinguishable from this one but entirely lacking conscious experience. Since such a world is conceivable, Chalmers claims, it
4508-404: The actual world obtains. The general argument goes as follows. Q can be false in a possible world if any of the following obtains: (1) there exists at least one invert relative to the actual world; (2) there is at least one absent quale relative to the actual world; (3) all actually conscious beings are p-zombies (all actual qualia are absent qualia). Another way to construe the zombie hypothesis
4600-413: The actual world. We can then, using the material conditional "→", represent a priori physicalism as the thesis that PTI → N is knowable a priori. An important wrinkle here is that the concepts in N must be possessed non-deferentially in order for PTI → N to be knowable a priori. The suggestion, then, is that possession of the concepts in the consequent , plus the empirical information in the antecedent
4692-430: The argument claims to prove. Richard Brown agrees that the zombie argument is circular. To show this, he proposes "zoombies", which are creatures non physically identical to people in every way and lacking phenomenal consciousness. If zoombies existed, they would refute dualism because they would show that consciousness is indeed physical. Paralleling the argument from Chalmers: It is conceivable that zoombies exist, so it
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#17328596000904784-736: The argument's logical validity include George Bealer . In his 2019 update to the article on philosophical zombies in the Stanford Encyclopedia of Philosophy , Kirk summed up the current state of the debate: In spite of the fact that the arguments on both sides have become increasingly sophisticated—or perhaps because of it—they have not become more persuasive. The pull in each direction remains strong. A 2013 survey of professional philosophers by Bourget and Chalmers found that 36% said p-zombies were conceivable but metaphysically impossible; 23% said they were metaphysically possible; 16% said they were inconceivable; and 25% responded "other". In 2020,
4876-434: The basis of a physicalist argument is that the world is defined entirely by physicality; thus, a world that was physically identical would necessarily contain consciousness, as consciousness would necessarily be generated from any set of physical circumstances identical to our own. The zombie argument claims that one can tell by the power of reason that such a "zombie scenario" is metaphysically possible. Chalmers writes, "From
4968-433: The big step has already been taken with micropsychism, the admission that at least some ultimates must be experiential. 'And were the inmost essence of things laid open to us' I think that the idea that some but not all physical ultimates are experiential would look like the idea that some but not all physical ultimates are spatio-temporal (on the assumption that spacetime is indeed a fundamental feature of reality). I would bet
5060-462: The blockers problem. With regard to the former, (3) gives the correct result that a purely physical world is one at which physicalism is true, since worlds in which there is some extra stuff are positive duplicates of a purely physical world. With regard to the latter, (3) appears to have the consequence that worlds in which there are blockers are worlds where positive non-physical properties of w 1 will be absent, hence w 1 will not be counted as
5152-474: The case of machine or alien intelligence). For in this case, the neurological terms translating a psychological term must be disjunctions over the possible instantiations, and it is argued that no physical law can use these disjunctions as terms. Type physicalism was the original target of the multiple realizability argument, and it is not clear that token physicalism is susceptible to objections from multiple realizability. There are two versions of emergentism,
5244-498: The conceivability of zombies, proponents of the argument infer their metaphysical possibility" and argues that this inference, while not generally legitimate, is legitimate for phenomenal concepts such as consciousness since we must adhere to "Kripke's insight that for phenomenal concepts, there is no gap between reference-fixers and reference (or between primary and secondary intentions)." That is, for phenomenal concepts, conceivability implies possibility. According to Chalmers, whatever
5336-661: The counterfeit bill example brought forth by Amy Kind. Kind's example centers around a counterfeit 20-dollar bill made to be exactly like an authentic 20-dollar bill. This is logically possible. Yet the counterfeit bill would not have the same value. According to Kind, in her book Philosophy of Mind: The Basics , The Zombie Argument can be put in this standard form from a dualist point of view: Zombies, creatures that are microphysically identical to conscious beings but that lack consciousness entirely, are conceivable. If zombies are conceivable then they are possible. Therefore, zombies are possible. If zombies are possible, then consciousness
5428-630: The definition of "physical" and the meaning of physicalism have been debated. Physicalism is closely related to materialism , and has evolved from materialism with advancements in the physical sciences in explaining observed phenomena. The terms "physicalism" and "materialism" are often used interchangeably, but can be distinguished on the basis that physics describes more than just matter. Physicalism encompasses matter , but also energy , physical laws , space , time , structure , physical processes, information , state, and forces , among other things, as described by physics and other sciences, all within
5520-512: The existence of first-personal facts, is evidence against physicalist theories of consciousness and against other third-personal metaphysical pictures, including standard versions of dualism. List also argues that the vertiginous question implies a "quadrilemma" for theories of consciousness, where no theory of consciousness can simultaneously respect four initially plausible metaphysical claims – namely, "first-person realism", "non-solipsism", "non-fragmentation", and "one world" – but that any three of
5612-408: The former does not rule out the possibility of non-supervenient properties (provided that they are associated only with physical particulars). Second, supervenience physicalism does not imply token physicalism, for the former allows supervenient objects (such as a "nation", or "soul") that are not equal to any physical object. There are multiple versions of reductionism. In the context of physicalism,
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#17328596000905704-439: The individual properties. The point of this extension is that physicalists usually suppose the existence of various abstract concepts which are non-physical in the ordinary sense of the word; so physicalism cannot be defined in a way that denies the existence of these abstractions. Also, physicalism defined in terms of supervenience does not entail that all properties in the actual world are type identical to physical properties. It
5796-403: The late philosopher of science and logical empiricist Carl Gustav Hempel ): an argument against theory-based understandings of the physical. Very roughly, Hempel's dilemma is that if we define the physical by reference to current physics, then physicalism is very likely to be false, as it is very likely (by pessimistic meta-induction ) that much of current physics is false. But if we instead define
5888-487: The mental and the physical. In physicalism, material facts determine all other facts. Since any fact other than that of consciousness may be held to be the same for a p-zombie and for a normal conscious human, it follows that physicalism must hold that p-zombies are either not possible or are the same as normal humans. The zombie argument is a version of general modal arguments against physicalism, such as that of Saul Kripke . Further such arguments were notably advanced in
5980-404: The mind. Physicist Adam Brown has suggested constructing a type of philosophical zombie using counterfactual quantum computation , a technique in which a computer is placed into a superposition of running and not running. If the program being executed is a brain simulation, and if one makes the further assumption that brain simulations are conscious, then the simulation can have the same output as
6072-441: The modal status of physicalism: whether it is a necessary truth or is only true in a world that conforms to certain conditions (i.e. those of physicalism). Closely related to supervenience physicalism is realisation physicalism, the thesis that every instantiated property is either physical or realised by a physical property. Token physicalism is the proposition that "for every actual particular (object, event or process) x, there
6164-421: The ordinary sense. It is common to express the notion of "metaphysical or logical combination of properties" using the notion of supervenience : A property A is said to supervene on a property B if any change in A necessarily implies a change in B . Since any change in a combination of properties must consist of a change in at least one component property, we see that the combination does indeed supervene on
6256-401: The phenomenal concept strategy is a label for those a posteriori physicalists who attempt to show that it is only the concept of consciousness—not the property —that is in some way "special" or sui generis . Other a posteriori physicalists eschew the phenomenal concept strategy, and argue that even ordinary macroscopic truths such as "water covers 60% of the earth's surface" are not knowable
6348-500: The philosopher David Chalmers , argue that since a philosophical zombie is by definition physically identical to a conscious person, even its logical possibility refutes physicalism. This is because it establishes the existence of conscious experience as a further fact . Philosopher Daniel Stoljar points out that zombies need not be utterly without subjective states, and that even a subtle psychological difference between two physically identical people, such as how coffee tastes to them,
6440-411: The physical components of the world and is not necessitated by them (does not supervene on them). To handle the epiphenomenal ectoplasm problem, (1) can be modified to include a "that's-all" or "totality" clause or be restricted to "positive" properties. Adopting the former suggestion here, we can reformulate (1) as follows: (2) Physicalism is true at a possible world w if and only if any world that
6532-412: The physical in terms of a future (ideal) or completed physics, then physicalism is hopelessly vague or indeterminate. While the force of Hempel's dilemma against theory-based conceptions of the physical remains contested, alternative "non-theory-based" conceptions of the physical have also been proposed. Frank Jackson , for example, has argued in favour of the aforementioned "object-based" conception of
6624-473: The physical makes core non-physical entities of non-physicalist metaphysics, like God, Cartesian souls and abstract numbers, physical, and thus either false or trivially true: "God is non-mentally-and-non-biologically identifiable as the thing that created the universe. Supposing emergentism is true, non-physical emergent properties are non-mentally-and-non-biologically identifiable as non-linear effects of certain arrangements of matter. The immaterial Cartesian soul
6716-518: The physical properties at w 1 . Since (2) rules out worlds that are physical duplicates of w 1 and also contain non-physical interveners by virtue of the minimality, or that's-all clause, (2) gives the (allegedly) incorrect result that physicalism is true at w 1 . One response to this problem is to abandon (2) in favour of the possibility mentioned earlier in which supervenience-based formulations of physicalism are restricted to what David Chalmers calls "positive properties". A positive property
6808-453: The physical. An objection to this proposal, which Jackson noted, is that if it turns out that panpsychism or panprotopsychism is true, then such a non-materialist understanding of the physical gives the counterintuitive result that physicalism is nevertheless also true, since such properties will figure in a complete account of paradigmatic examples of the physical. David Papineau and Barbara Montero have advanced and subsequently defended
6900-458: The possession of most, if not all other empirical concepts, the possession of consciousness has the special property that the presence of PTI and the absence of consciousness will be conceivable—even though, according to them, it is knowable a posteriori that PTI and not Q is not metaphysically possible. These a posteriori physicalists endorse some version of what Daniel Stoljar (2005) has called "the phenomenal concept strategy ". Roughly speaking,
6992-409: The reductions referred to are of a "linguistic" nature, allowing discussions of, say, mental phenomena to be translated into discussions of physics. In one formulation, every concept is analysed in terms of a physical concept. One counterargument to this supposes there may be an additional class of expressions that is non-physical but increases a theory's expressive power. Another version of reductionism
7084-599: The same general form. The premises of the general zombie argument are implied by the premises of all the specific zombie arguments. A general zombie argument is in part motivated by potential disagreements between various anti-physicalist views. For example, an anti-physicalist view can consistently assert that p-zombies are metaphysically impossible but that inverted qualia (such as inverted spectra ) or absent qualia (partial zombiehood) are metaphysically possible. Premises regarding inverted qualia or partial zombiehood can replace premises regarding p-zombies to produce variations of
7176-682: The same survey yielded almost identical results: "inconceivable" 16%, conceivable but impossible 37%, "metaphysically possible" 24%, and "other" 23%. Though philosophical zombies are widely used in thought experiments, the detailed articulation of the concept is not always the same. P-zombies were introduced primarily to argue against specific types of physicalism such as materialism and behaviorism , according to which mental states exist solely as behavior. Belief, desire, thought, consciousness, and so on, are conceptualized as behavior (whether external behavior or internal behavior) or tendencies towards behaviors. A p-zombie behaviorally indistinguishable from
7268-442: The sky seem blue), she has never seen color. If Mary were released from this room and experienced color for the first time, would she learn anything new? Jackson initially believed this supported epiphenomenalism (mental phenomena are the effects, but not the causes, of physical phenomena) but later changed his view to physicalism , suggesting that Mary is simply discovering a new way for her brain to represent qualities that exist in
7360-525: The strong version and the weak version. Supervenience physicalism has been seen as a strong version of emergentism, in which the subject's psychological experience is considered genuinely novel. Non-reductive physicalism, on the other side, is a weak version of emergentism because it does not need that the subject's psychological experience be novel. The strong version of emergentism is incompatible with physicalism. Since there are novel mental states, mental states are not nothing over and above physical states. But
7452-416: The subject cannot actually read, but is able to manipulate meaningfully using a set of algorithms. Searle holds that a program cannot give a computer a "mind" or "understanding", regardless of how intelligently it may make it behave. Stevan Harnad argues that Searle's critique is really meant to target functionalism and computationalism , and to establish neuroscience as the only correct way to understand
7544-685: The term "zimboes"—p-zombies that have second-order beliefs —to argue that the idea of a p-zombie is incoherent; "Zimboes think they are conscious, think they have qualia, think they suffer pains—they are just 'wrong' (according to this lamentable tradition), in ways that neither they nor we could ever discover!". Michael Lynch agrees with Dennett, arguing that the zombie conceivability argument forces us to either question whether we actually have consciousness or accept that zombies are not possible. If zombies falsely believe they are conscious, how can we be sure we are not zombies? We may believe we are experiencing conscious mental states when in fact we merely hold
7636-759: The thesis that physical stuff is, in itself, in its fundamental nature, something wholly and utterly non-experiential... even when they are prepared to admit with Eddington that physical stuff has, in itself, 'a nature capable of manifesting itself as mental activity', i.e. as experience or consciousness". Because experiential phenomena allegedly cannot be emergent from wholly non-experiential phenomena, philosophers are driven to substance dualism , property dualism , eliminative materialism and "all other crazy attempts at wholesale mental-to-non-mental reduction". Real physicalists must accept that at least some ultimates are intrinsically experience-involving. They must at least embrace micropsychism . Given that everything concrete
7728-400: The view that conceivability can tell us about possibility, he provides no positive defense of the principle. As an analogy, the generalized continuum hypothesis has no known counterexamples, but this does not mean we must accept it. Indeed, according to Hill and McLaughlin, the fact that Chalmers concludes we have epiphenomenal mental states that do not cause our physical behavior seems to be
7820-559: The weak version of emergentism is compatible with physicalism. Emergentism is a very broad view. Some forms of it appear either incompatible with physicalism or equivalent to it (e.g. posteriori physicalism); others appear to merge both dualism and supervenience. Emergentism compatible with dualism claims that mental states and physical states are metaphysically distinct while maintaining the supervenience of mental states on physical states. But this contradicts supervenience physicalism, which denies dualism. Physicalists hold that physicalism
7912-421: The word) properties of the actual world are also instantiated. To borrow a metaphor from Saul Kripke , the truth of physicalism at the actual world entails that once God has instantiated or "fixed" the physical properties and laws of our world, then God's work is done; the rest comes "automatically". But (1) fails to capture even a necessary condition for physicalism to be true at a world w . To see this, imagine
8004-408: The world. Swampman is an imaginary character introduced by Donald Davidson . If Davidson goes hiking in a swamp and is struck and killed by a lightning bolt while nearby another lightning bolt spontaneously rearranges a bunch of molecules so that, entirely by coincidence, they take on exactly the same form that Davidson's body had at the moment of his untimely death, then this being, "Swampman", has
8096-421: The zombie argument may think that conceptual analysis is a central part of (if not the only part of) philosophy and that it certainly can do a great deal of philosophical work. But others, such as Dennett, Paul Churchland and W.V.O. Quine , have fundamentally different views. For this reason, discussion of the zombie argument remains vigorous in philosophy. Some accept modal reasoning in general but deny it in
8188-463: The zombie argument. The metaphysical possibility of a physically indistinguishable world with either inverted qualia or partial zombiehood implies that physical truths do not metaphysically necessitate phenomenal truths. To construct the general form of the zombie argument, take the sentence P to be true if and only if the conjunct of all microphysical truths of our world obtain, and take the sentence Q to be true if some phenomenal truth that obtains in
8280-460: The zombie case. Christopher S. Hill and Brian P. McLaughlin suggest that the zombie thought experiment combines imagination of a "sympathetic" nature (putting oneself in a phenomenal state) and a "perceptual" nature (imagining becoming aware of something in the outside world). Each type of imagination may work on its own but not work when used at the same time. Hence Chalmers's argument need not go through. Moreover, while Chalmers defuses criticisms of
8372-436: The zombie is that of a human completely lacking conscious experience. It is possible to distinguish various zombie subtypes used in different thought experiments as follows: Zombie arguments often support lines of reasoning that aim to show that zombies are metaphysically possible in order to support some form of dualism —in this case the view that the world includes two kinds of substance (or perhaps two kinds of property ):
8464-717: Was philosopher Robert Kirk who first used the term "zombie" in this context, in 1974. Before that, Keith Campbell made a similar argument in his 1970 book Body and Mind , using the term "imitation man". Chalmers further developed and popularized the idea in his work. There has been a lively debate about what the zombie argument shows. Critics who primarily argue that zombies are not conceivable include Daniel Dennett , Nigel J. T. Thomas, David Braddon-Mitchell, and Robert Kirk. Critics who assert mostly that conceivability does not entail possibility include Katalin Balog, Keith Frankish , Christopher Hill , and Stephen Yablo . Critics who question
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