Editing Mind–body dualism (section)

===Argument from physics===
The argument from physics is closely related to the argument from causal interaction. Many physicists and consciousness researchers have argued that any action of a nonphysical mind on the brain would entail the violation of physical laws, such as the [[conservation of energy]].<ref>Wilson, D. L. 1999. "Mind-brain interaction and the violation of physical laws." pp. 185–200 in ''The Volitional Brain'', edited by B. Libet, A. Freeman, and K. Sutherland. Thorverton, UK: Imprint Academic.</ref><ref>Mohrhoff, U. 1999. "The physics of interaction." pp. 165–184 in ''The Volitional Brain'', edited by B. Libet, A. Freeman, and K. Sutherland. Thorverton, UK: Imprint Academic.</ref><ref>{{cite journal | last1 = Jaswal | first1 = L | year = 2005 | title = Isolating disparate challenges to Hodgson's account of free will | journal = Journal of Consciousness Studies | volume = 12 | issue = 1 |pages = 43–46}}</ref><ref>{{cite journal | last1 = Clark | first1 = T. W. | year = 2005a | title = Hodgson's black box | journal = Journal of Consciousness Studies | volume = 12 | issue = 1 |pages = 38–59}}</ref>

By assuming a deterministic physical universe, the objection can be formulated more precisely. When a person decides to walk across a room, it is generally understood that the decision to do so, a mental event, immediately causes a group of neurons in that person's brain to fire, a physical event, which ultimately results in his walking across the room. The problem is that if there is something totally non-physical ''causing'' a bunch of neurons to fire, then there is no ''physical'' event which causes the firing. This means that some physical energy is required to be generated against the physical laws of the deterministic universe—this is by definition a miracle and there can be no scientific explanation of (repeatable experiment performed regarding) where the ''physical'' energy for the firing came from.<ref>Baker, Gordon and Morris, Katherine J. (1996) ''Descartes' Dualism'', London: Routledge.</ref> Such interactions would violate the fundamental [[physical law|laws of physics]]. In particular, if some external source of energy is responsible for the interactions, then this would violate the law of the [[conservation of energy]].<ref>[[William Lycan|Lycan, William]]. 1996. "Philosophy of Mind." In ''[[The Blackwell Companion to Philosophy]]'', edited by N. Bunnin and E. P. Tsui-James. Oxford: Blackwell Publishers.</ref> Dualistic interactionism has therefore been criticized for violating a general [[heuristic]] principle of science: the [[causal closure]] of the physical world.

====Replies====
The ''[[Stanford Encyclopedia of Philosophy]]''<ref name="SEP" /> and the ''[[New Catholic Encyclopedia]]''<ref name="CathEn">Maher, Michael (1909) "The Law of Conservation of Energy", ''Catholic Encyclopedia'', vol. 5, pp. 422 ff, {{cite web |url=http://www.newadvent.org/cathen/05422a.htm |title=Catholic Encyclopedia: The Law of Conservation of Energy |access-date=2007-05-20 |url-status=live |archive-url=https://web.archive.org/web/20070701235022/http://www.newadvent.org/cathen/05422a.htm |archive-date=2007-07-01}}.</ref> provide two possible replies to the above objections. The first reply is that the mind may influence the ''distribution'' of energy, without altering its quantity. The second possibility is to deny that the human body is causally closed, as the [[conservation of energy]] applies only to closed systems. However, physicalists object that no evidence exists for the causal non-closure of the human body.<ref>{{cite book|last=Murphy|first=Nancy|title=Downward Causation and the Neurobiology of Free Will|year=2009|publisher=Springer|isbn=978-3642032042}}</ref> [[Robin Collins]] responds<ref>[[Robin Collins|Collins, Robin]]. 2008. "Modern Physics and the Energy Conservation Objection to Mind-Body Dualism." ''The American Philosophical Quarterly'' 45(1):31–42.</ref> that energy conservation objections misunderstand the role of energy conservation in physics. Well understood scenarios in general relativity violate energy conservation and quantum mechanics provides precedent for causal interactions, or correlation without energy or momentum exchange.<ref>{{cite web |url=http://www.newdualism.org/papers/R.Collins/EC-PEC.htm |title=Modern Physics and the Energy Conservation Objection to Mind-Body Dualism, by Robin Collins |access-date=2017-07-01 |url-status=live |archive-url=https://web.archive.org/web/20170625152408/http://www.newdualism.org/papers/R.Collins/EC-PEC.htm |archive-date=2017-06-25}}</ref> However, this does not mean the mind spends energy and, despite that, it still doesn't exclude the supernatural.

Another reply is akin to parallelism—Mills holds that behavioral events are causally [[overdetermination|overdetermined]], and can be explained by either physical or mental causes alone.<ref>{{cite journal|last=Mills|first=E.|title=Interactionism and Overdetermination|journal=American Philosophical Quarterly|year=1996|volume=33|pages=105–117}}</ref> An overdetermined event is fully accounted for by multiple causes at once.<ref>{{cite book|last=Althusser|first=Louis|title="Contradiction and Overdetermination," in For Marx|year=1985|publisher=Verso |isbn=978-0-902308-79-4}}</ref> However, [[J. J. C. Smart]] and [[Paul Churchland]] have pointed out that if physical phenomena fully determine behavioral events, then by [[Occam's razor]] an unphysical mind is unnecessary.<ref>{{cite book|last=Churchland|first=Paul|title=Matter and Consciousness, Revised Edition|year=1984|publisher=MIT Press|isbn=978-0262530743}}</ref>

Howard Robinson suggests that the interaction may involve [[dark energy]], [[dark matter]] or some other currently unknown scientific process.<ref name="Rob" />

Another reply is that the interaction taking place in the human body may not be described by "billiard ball" [[classical mechanics]]. If a nondeterministic interpretation of [[quantum mechanics]] is correct then microscopic events are [[indeterminism|indeterminate]], where the degree of [[determinism]] increases with the scale of the system. Philosophers [[Karl Popper]] and [[John Carew Eccles|John Eccles]] and physicist [[Henry Stapp]] have theorized that such indeterminacy may apply at the macroscopic scale.<ref>[[Karl Popper|Popper, Karl R.]], and [[John Eccles (neurophysiologist)|John C. Eccles]]. 1977. ''The Self and Its Brain''. Berlin: Springer.</ref> However, [[Max Tegmark]] has argued that classical and quantum calculations show that [[quantum decoherence]] effects do not play a role in brain activity.<ref>{{cite journal|last=Tegmark|first=Max|title=Importance of quantum decoherence in brain processes|journal=Phys. Rev. E|date=April 2000|volume=61|issue=4|pages=4194–4206|doi=10.1103/PhysRevE.61.4194|pmid=11088215|arxiv=quant-ph/9907009|bibcode=2000PhRvE..61.4194T|s2cid=17140058}}</ref>

Yet another reply to the interaction problem is to note that it doesn't seem that there is an interaction problem for all forms of substance dualism. For instance, [[Thomism|Thomistic]] dualism doesn't obviously face any issue with regards to interaction, for in this view the soul and the body are related as form and matter.<ref>{{cite web |url=http://edwardfeser.blogspot.com/2016/09/mind-body-interaction-whats-problem.html |title=Edward Feser: Mind-body interaction: What's the problem? |access-date=2017-04-24 |url-status=live |archive-url=https://web.archive.org/web/20170425032034/http://edwardfeser.blogspot.com/2016/09/mind-body-interaction-whats-problem.html |archive-date=2017-04-25 |date=2016-09-17}}</ref>