Philosophical zombie

{{sources needed}}
[[File:StDenys.jpg|thumb|right|174px|Saint Denis of Paris, famous philosophical zombie.]]
{{philosophy}}
A '''philosophical zombie''' or '''p-zombie''' is a hypothetical being that is physically indistinguishable from a [[human]] being in both appearance and behavior, but lacks conscious experiences. It's a concept related to the problem of other minds. 

There are philosophers who actually take this notion seriously and consider that the p-zombie thought experiment is sufficient to prove some kind of [[dualism]].<ref group=note>Or disprove materialism. Expect hair-splitting.</ref> Others are less inclined to state the thought experiment "proves" dualism, but take it seriously as illustrative of the hard problem of consciousness and why it requires a serious solution. 

==History==

The concept of a machine acting like a [[Human| human being]] without having [[consciousness]] dates back to [[Rene Descartes]] (1596-1650). {{wpl|Robert Kirk (philosopher)|Robert Kirk}} introduced the term "zombie" within a philosophical context in 1974, and [[Daniel Dennett]] popularized it in 1991.<ref>For example: {{cite book
 | last1 = Dennett
 | first1 = Daniel C.
 | author-link1 = Daniel Dennett
 | orig-year = 1991
 | title = Consciousness Explained
 | url = https://books.google.com/books?id=ZG0SDgAAQBAJ
 | publisher = Little, Brown
 | publication-date = 2017
 | page = 
 | isbn = 9780316439480
 | access-date = 19 November 2019
 | quote = A philosopher's zombie, you will recall, is behaviorally indistinguishable from a normal human being, but is not conscious.}}</ref>
At some stage, a person or persons unknown expanded the term "zombie" to "philosophical zombie" — to distinguish the philosophical concept from the [[zombies]] of the Haitian [[Vodun|voodoo]] tradition and from the zombies in monster movies. This was then abbreviated to "p-zombie".

==Types==

Taxonomists of the p-zombie phenomenon can distinguish several different kinds of p-zombies, depending on how they are indistinguishable from humans and what specific human quality they lack.

*A p-zombie might just be behaviorally indistinguishable from a human being. Dissecting such a zombie, we might find that it differs completely from a real human being.
*A p-zombie might be functionally equivalent with human beings. That is, such a p-zombie might have a brain made of wires and transistors, but those wires and transistors would correspond to the axons and neurons of a human brain, and it would be possible to map one to the other.
*A p-zombie may be in every way equivalent to a human being, but only be simulating the exact way a human would react without consciously experiencing events.
*A p-zombie might also be physically identical with a human being. Assuming that such a p-zombie is different from a human being would require some kind of [[dualism]] or [[idealism]].

Furthermore, there are several different qualities a p-zombie might lack. Often, a p-zombie is assumed to lack [[qualia]], but other possiblly missing qualities are intentionality, [[free will]], [[consciousness]], or a [[soul]].

==Chalmers' p-zombies==
Maybe the most important presentation of p-zombies in contemporary philosophy was made by David Chalmers in the 1990s.<ref name="ConsciousMind">Chalmers, David. ''The Conscious Mind''. Oxford University Press, 1996.</ref> Chalmers's core argument is roughly:

P1: P-zombies are conceivable.

P2: If p-zombies are conceivable, then they are metaphysically possible.

C1: So, p-zombies are metaphysically possible.

P3: If p-zombies are metaphysically possible, then physicalism<ref group="note">The metaphysical thesis that everything is physical</ref> is false.

C2: So, physicalism is false.

Philosophers' objections tend to concentrate on the first two premises, and Chalmers goes to some lengths to describe a notion of conceivability that secures metaphysical possibility and show that p-zombies fall under this notion.<ref>Chalmers, David. Does Conceivability Entail Possibility? In ''Conceivability and Possibility'', T. Gendler & J. Hawthorne, eds. Oxford University Press, 2002, 145-200.</ref> Importantly, the argument does not depend on the ''physical'' possibility of p-zombies<ref group="note">Contemporary philosophy distinguishes between numerous types of possibility. For instance, something is physically possible if it is possible given the (actual) laws of physics, epistemically possible if possible given everything you (in some cases, we) know, doxastically possible (for you) given everything you believe, etc.</ref> &mdash; in fact, Chalmers does not believe that p-zombies could exist in the actual world. There is no suggestion that any actual person might secretly be a p-zombie. Rather, what Chalmers argues is that, for some (specialized) sense of "could", it could have been the case that the world was physically identical to the actual world and yet there be no conscious experience.

Chalmers' zombie argument is made as part of an argument for a kind of ''property dualism'', which he describes as involving "properties of an individual that are not entailed by the physical properties of that individual, although they may depend lawfully on those properties".<ref name="ConsciousMind" /> This is a weaker version of dualism than the better known substance dualism familiar to many from Descartes, who posited a distinct mental substance. Chalmers goes on to argue that the dualism he advocates is naturalistic, compatible with contemporary scientific knowledge.<ref name="ConsciousMind />

===Objections===

One prominent objection, made by Daniel Dennett among others, is that zombies are not even conceivable.<ref name="SEPZombies">Kird, Robert. Zombies. ''Stanford Encyclopedia of Philosophy'', 2023.</ref> Dennett argues that proponents of the zombie argument fail to imagine zombies in adequate detail because neural functions are highly sensitive to fine structures;<ref>Dennett, Daniel. 'The Zombie Hunch: Extinction of an Intuition?' ''Cambridge University Press''.</ref> he extends this to argue that zombie intuitions are self-undermining. Others have argued that the conceivability of p-zombies would entail that conscious experiences have no causal effects, and that this is implausible.<ref name="SEPZombies" />

The second major category of objections are those against the inference from conceivability to possibility. Some philosophers have argued that the conceivability of zombies does not entail the relevant ''kind'' of possibility. Two grounds for this objection are the gap between the epistemic premise of conceivability and the metaphysical conclusion of Chalmers' argument and the inference from features of our conceptual understanding of conscious experience to the existence of real non-physical properties in the world.<ref name="SEPZombies" />

==Popular argument==

Outside the academy, a number of popular variants of the zombie argument have developed. They generally do not carry through the conceptual distinctions made by Chalmers. Often, p-zombies are presented as things which might exist in the actual world. This is sometimes accompanied by the suggestion that ''somebody you know'' might actually be a zombie.<ref>Reply to 'ELI5: What is a P-Zombie'. r/explainlikeimfive. [https://www.reddit.com/r/explainlikeimfive/comments/9noxm2/eli5_what_is_a_pzombie/?rdt=44241 Reddit].</ref> Such claims are relatively strong, and so open to distinctive objections.

===Objections===

A common objection is that [[Circular reasoning|the concept does not make sense ''without'' assuming dualism in the first place]], thus the idea is [[begging the question]].

It does make for an interesting enough [[thought experiment]], where you can ask how you'd tell p-zombies apart from "real" humans, even extending to how you could tell that you, yes ''you'', aren't a p-zombie at all. Indeed, if there is no answer, then the soul is [[unfalsifiable]] by the limits imposed on it by this thought experiment itself and so doesn't exist or have any bearing on our lives in any meaningful way — belief in it wouldn't even be trivial. If, on the other hand, an observable difference was proposed, the soul would cease to be supernatural, and again, the thought experiment that set out to prove the soul exists in fact disproves it, or at least certain attributes of it.

The other objection is against the conceptual ''existence'' of p-zombies, as thinking you can conceive of something doesn't mean the universe gives a shit. Religious apologists have [[Ontological argument|tried that one]] already.

It has ''also'' been pointed out that the arguments in favor of p-zombies are eerily similar to those used in order to justify slavery and oppression in eras past.<ref>[http://www.skepdic.com/zombies.html zombies and p-zombies]. ''The Skeptic's Dictionary'', 4 August 2016.</ref> In the future, the philosophical zombie argument could be uncritically applied to any robot even if one would otherwise have to conclude it was even more intelligent, sentient, and conscious than your typical human (some science fiction explores exactly this).

==Conclusions==
The concept of a p-zombie is a two-edged sword. On the one hand, if it is possible to show that p-zombies can exist, then the theory of eliminative [[materialism]] is in trouble, since it would seem that there are phenomena which can't be reduced to strictly materialistic causes. Proving that p-zombies can exist is impossible unless we can define them. Could an entity lacking consciousness be indistinguishable in all material respects from a conscious human being? Since we do not know what causes consciousness, all we can currently say given present scientific knowledge is that we don't know. Furthermore, there is sometimes a confusion between whether practically or theoretically detectable differences are meant; if consciousness has a material basis, there are certainly material differences between conscious and unconscious beings, regardless of whether or not scientists can detect these differences using the current means of measurement at their disposal.

On the other hand, p-zombies can be used to attempt to show that several concepts like the irreducibility of qualia don't make sense, since they would allow the existence of p-zombies, without any means to distinguish them from ordinary people. Some have even argued that it then would be impossible to know if oneself is or is not a p-zombie. The third type of p-zombie, indeed, might be indistinguishable by any means, considering that there is no physical evidence for the existence of a soul.

It's also a good way to justify callous treatment of your fellow human beings. People will still heavily dislike you for it.

==See also==
*[[Chinese room]]
*[[Alt-right glossary#NPC|NPC]] — an [[alt-right]] term for demeaning the [[left-wing]]
*[[Solipsism]], the belief that ''everyone'' on Earth other than you is a p-zombie.
*[[Turing test]]
*[[Zombies]]

==External links==
* [http://lesswrong.com/lw/pn/zombies_the_movie/ The p-zombie movie], [[LessWrong]] - ''"I'm [[Daniel Dennett]], bitches!"''
*[http://rationallyspeaking.blogspot.com/2008/07/zombification-of-philosophy-of-mind.html The zombification of philosophy (of mind)], [[Massimo Pigliucci]]
==Notes==
{{reflist|group=note}}
==References==
{{reflist|2|80%}}

[[Category:Philosophy]]
[[Category:Thought experiment]]

Categories: Philosophy, Thought experiment