Editing Consciousness (section)

===Mind–body problem===
{{Main|Mind–body problem}}

[[Image:Descartes mind and body.gif|thumb|Illustration of [[mind–body dualism]] by [[René Descartes]]. Inputs are passed by the sensory organs to the [[pineal gland]], and from there to the immaterial [[Soul|spirit]].]]

Mental processes (such as consciousness) and physical processes (such as brain events) seem to be correlated, however the specific nature of the connection is unknown.

The first influential philosopher to discuss this question specifically was Descartes, and the answer he gave is known as [[mind–body dualism]]. Descartes proposed that consciousness resides within an immaterial domain he called ''[[mental substance|res cogitans]]'' (the realm of thought), in contrast to the domain of material things, which he called ''[[res extensa]]'' (the realm of extension).<ref>{{cite book|title=Philosophy of Man: selected readings|last=Dy|first=Manuel B. Jr.|publisher=Goodwill Trading Co.|year=2001|isbn=978-971-12-0245-3|page=97}}</ref> He suggested that the interaction between these two domains occurs inside the brain, perhaps in a small midline structure called the [[pineal gland]].<ref name="S_pineal">{{cite web|title=Descartes and the Pineal Gland|publisher=Stanford University|date=November 5, 2008|url=http://plato.stanford.edu/entries/pineal-gland/|access-date=2025-02-07|archive-date=2019-12-16|archive-url=https://web.archive.org/web/20191216035157/https://plato.stanford.edu/entries/pineal-gland/|url-status=live}}</ref>

Although it is widely accepted that Descartes explained the problem cogently, few later philosophers have been happy with his solution, and his ideas about the pineal gland have especially been ridiculed.<ref name="S_pineal" /> However, no alternative solution has gained general acceptance. Proposed solutions can be divided broadly into two categories: [[dualism (philosophy of mind)|dualist]] solutions that maintain Descartes's rigid distinction between the realm of consciousness and the realm of matter but give different answers for how the two realms relate to each other; and [[monism|monist]] solutions that maintain that there is really only one realm of being, of which consciousness and matter are both aspects. Each of these categories itself contains numerous variants. The two main types of dualism are [[substance dualism]] (which holds that the mind is formed of a distinct type of substance not governed by the laws of physics), and [[property dualism]] (which holds that the laws of physics are universally valid but cannot be used to explain the mind). The three main types of [[monism]] are physicalism (which holds that the mind is made out of matter), [[idealism]] (which holds that only thought or experience truly exists, and matter is merely an illusion), and [[neutral monism]] (which holds that both mind and matter are aspects of a distinct essence that is itself identical to neither of them). There are also, however, a large number of idiosyncratic theories that cannot cleanly be assigned to any of these schools of thought.<ref>{{cite book|author=William Jaworski|title=Philosophy of Mind: A Comprehensive Introduction|publisher=John Wiley and Sons|year=2011|isbn=978-1-4443-3367-1|pages=5–11}}</ref>

Since the dawn of Newtonian science with its vision of simple mechanical principles governing the entire universe, some philosophers have been tempted by the idea that consciousness could be explained in purely physical terms. The first influential writer to propose such an idea explicitly was [[Julien Offray de La Mettrie]], in his book ''[[Man a Machine]]'' (''L'homme machine''). His arguments, however, were very abstract.<ref name=LaMettrie>{{cite book| editor=Ann Thomson|author=Julien Offray de La Mettrie|title=Machine man and other writings|publisher=Cambridge University Press|year=1996|isbn=978-0-521-47849-6|author-link=Julien Offray de La Mettrie}}</ref> The most influential modern physical theories of consciousness are based on [[psychology]] and [[neuroscience]]. Theories proposed by neuroscientists such as [[Gerald Edelman]]<ref>{{cite book|title=Bright Air, Brilliant Fire: On the Matter of the Mind|author=Gerald Edelman|publisher=Basic Books|year=1993|isbn=978-0-465-00764-6|author-link=Gerald Edelman|url-access=registration|url=https://archive.org/details/brightairbrillia00gera}}</ref> and [[António Damásio|Antonio Damasio]],<ref name=DamasioFeeling>{{cite book|author=Antonio Damasio|year=1999|title=The Feeling of What Happens: Body and Emotion in the Making of Consciousness|location=New York|publisher=Harcourt Press|isbn=978-0-15-601075-7|author-link=Antonio Damasio|url=https://archive.org/details/feelingofwhathap00dama_0}}</ref> and by philosophers such as Daniel Dennett,<ref>{{cite book|author=Daniel Dennett|year=1991|title=Consciousness Explained|url=https://archive.org/details/consciousnessexp00denn|url-access=registration|location=Boston|publisher=Little & Company|isbn=978-0-316-18066-5|author-link=Daniel Dennett}}</ref> seek to explain consciousness in terms of neural events occurring within the brain. Many other neuroscientists, such as [[Christof Koch]],<ref name=KochQuest>{{cite book| author=Christof Koch|year=2004|title=The Quest for Consciousness|location=Englewood, CO|publisher=Roberts & Company|isbn=978-0-9747077-0-9|author-link=Christof Koch}}</ref> have explored the neural basis of consciousness without attempting to frame all-encompassing global theories. At the same time, [[computer scientist]]s working in the field of [[artificial intelligence]] have pursued the goal of creating digital computer programs that can [[Artificial consciousness|simulate or embody consciousness]].<ref>Ron Sun and Stan Franklin, Computational models of consciousness: A taxonomy and some examples. In: P.D. Zelazo, M. Moscovitch, and E. Thompson (eds.), ''The Cambridge Handbook of Consciousness'', pp. 151–174. Cambridge University Press, New York. 2007</ref>

A few theoretical physicists have argued that classical physics is intrinsically incapable of explaining the holistic aspects of consciousness, but that [[Quantum mechanics|quantum theory]] may provide the missing ingredients. Several theorists have therefore proposed [[quantum mind]] (QM) theories of consciousness.<ref name="Stanford_qm_cos">{{cite book|title=Quantum Approaches to Consciousness|publisher=Stanford University|date=December 25, 2011|url=http://plato.stanford.edu/entries/qt-consciousness/|access-date=December 25, 2011|archive-date=August 8, 2021|archive-url=https://web.archive.org/web/20210808080906/https://plato.stanford.edu/entries/qt-consciousness/|url-status=live}}</ref> Notable theories falling into this category include the [[holonomic brain theory]] of [[Karl H. Pribram|Karl Pribram]] and [[David Bohm]], and the [[Orch-OR|Orch-OR theory]] formulated by [[Stuart Hameroff]] and [[Roger Penrose]]. Some of these QM theories offer descriptions of phenomenal consciousness, as well as QM interpretations of access consciousness. None of the quantum mechanical theories have been confirmed by experiment. Recent publications by G. Guerreshi, J. Cia, S. Popescu, and H. Briegel<ref name="Cai2010">{{cite journal|doi=10.1103/PhysRevE.82.021921|pmid=20866851|last1=Cai|first1=J.|last2=Popescu|first2=S.|last3=Briegel|first3=H.|title=Persistent dynamic entanglement from classical motion: How bio-molecular machines can generate non-trivial quantum states|journal=Physical Review E|volume=82|issue=2|pages=021921|arxiv=0809.4906|bibcode=2010PhRvE..82b1921C|year=2010|s2cid=23336691}}</ref> could falsify proposals such as those of Hameroff, which rely on [[quantum entanglement]] in protein. At the present time many scientists and philosophers consider the arguments for an important role of quantum phenomena to be unconvincing.<ref>{{cite book|author=John Searle|year=1997|title=The Mystery of Consciousness|publisher=The New York Review of Books|pages=53–88|isbn=978-0-940322-06-6|author-link=John Searle}}</ref> Empirical evidence is against the notion of quantum consciousness, an experiment about [[wave function collapse]] led by [[Catalina Curceanu]] in 2022 suggests that quantum consciousness, as suggested by [[Roger Penrose]] and [[Stuart Hameroff]], is highly implausible.<ref name="Curceanuetal">{{cite journal|last1=Derakhshani|first1=Maaneli|last2=Diósi|first2=Lajos|last3=Laubenstein|first3=Matthias|last4=Piscicchia|first4=Kristian|last5=Curceanu|first5=Catalina|title=At the crossroad of the search for spontaneous radiation and the Orch OR consciousness theory|journal=Physics of Life Reviews|date=September 2022|volume=42|pages=8–14|doi=10.1016/j.plrev.2022.05.004|pmid=35617922|bibcode=2022PhLRv..42....8D|url=https://www.sciencedirect.com/science/article/abs/pii/S1571064522000197}}</ref>

Apart from the general question of the [[Hard problem of consciousness|"hard problem" of consciousness]] (which is, roughly speaking, the question of how mental experience can arise from a physical basis<ref>{{cite book|title=The Consciousness Paradox: Consciousness, Concepts, and Higher-Order Thoughts|author= Rocco J. Gennaro|chapter-url=https://books.google.com/books?id=t-XgKMgzwk4C&pg=PA75|page=75|chapter=§4.4 The hard problem of consciousness|isbn=978-0-262-01660-5|year=2011|publisher=MIT Press}}</ref>), a more specialized question is how to square the subjective notion that we are in control of our decisions (at least in some small measure) with the customary view of causality that subsequent events are caused by prior events. The topic of [[free will]] is the philosophical and scientific examination of this conundrum.