What is the best argument for dualism? Is it a plausible theory?

In this essay it shall be shown that dualism as proposed by Descartes is no longer useful due quantum mechanics revealing the distinction between mind and body to be illusory. The best argument for dualism will be put forward nonetheless, and found to be ultimately incomplete.

Cartesian dualism

In his Meditations on First Philosophy Descartes casts doubt on all beliefs and decides he cannot be certain the external world exists. The only thing he can be certain of is his own mind, “cogito ergo sum”, I think therefore I am, and concludes he is fundamentally “a thing that thinks” (Cottingham 1985) (as cited by Chalmers 2002, 11). In the sixth meditation he concludes the mental and physical are fundamentally distinct (Chalmers 2002).

His arguments are: - One can be certain about the mental but not about the physical; - The mind is indivisible while any physical entity is divisible - One can imagine oneself existing without a body, so one must be distinct from one’s body and likewise from any physical entity.

In The Passions of the Soul Descartes goes into more detail on how he believes the mind and body interact. He says that some of our perceptions are caused by the soul and others by the body. He also says that the soul is united to all parts of the body conjointly but its “seat” is in the pineal gland in the brain (Cottingham 1996) (as cited by Chalmers 2002, 22).

Where Cartesian dualism fails is where the body is categorized as being different to other seemingly external entities, for example:

“The body is a unity which is in a sense indivisible because of the arrangement of its organs, related to one another that the removal of any one of them renders the whole body defective” (Cottingham 1996) (as cited by Chalmers 2002, 22).

Is it not the case that the removal of air or gravity or sunlight or alteration of the position of the Milkyway galaxy in the Universe would render the whole body defective? His categorization cannot be justified. I argue that what Descartes calls the ‘soul’ is actually consciousness and is not contained in a person’s body but rather everything in existence is made of one consciousness and so everything is indivisible, which means all categorizations dividing reality are illusory. Therefore there is no fundamental dualistic division. To explain away the vagueness of this mystical claim a very brief rundown of quantum mechanics is required.

Quantum mechanics

Quantum mechanics is the study of the motion of sub-atomic particles, or ‘quanta’ of which all things that exist are made (http://en.wikipedia.org/). Some examples include photons (light particles), electrons, neutrons and protons. In the sub-atomic realm the laws of Newtonian physics and common sense rationality do not apply (Zukav 2001). For example, when a single photon is directed through two-slit grate the photon paradoxically goes through both slits at the same time, creating measurable interference - with itself. The photon somehow knows there are two slits (http://library.thinkquest.org). Is the photon conscious?

Furthermore, unlike the motion of things that are on a scale we are used to such as cars and footballs, it is not possible to measure both the position and momentum of sub-atomic particles. The more you know about the position, the less you can know about the momentum. If you focus on the exact position, you can know nothing whatsoever about the momentum, and vice versa. This is not due to equipment limitations, but rather the nature of sub-atomic particles (Zukav 2001).

According to quantum mechanics it is not possible even in principle to predict the future accurately. We can focus on only one thing precisely. This is known as Heisnburgs uncertainty principle (Zukav 2001). We must choose to what extent we measure the position or momentum of a particle.

In other words, consciousness is fundamentally entwined with existence. The question has been raised; did we create the particles we are experimenting with? After all, everything is made of them - including us. The Cartesian mind-body distinction is not the most fundamental distinction, if there is any distinction to be made at all.

Nobel Prize winning physicist Neils Bohr (1958) (as cited by Zukav 2001, 95) said:

“Light has no properties independent of us. This is the same as saying it does not exist. Without us, or anything else to interact with, light does not exist. And without light, or anything else for us to interact with, we do not exist”

This is known as complementarity. It is the strongest argument for dualism because it means there is an ‘us’ and an ‘it’. However, the ‘us’ and the ‘it’ paradoxically cause each other to simultaneously come into existence. Therefore to refer to this as dualism is to remain in a paradox. If the two halves are inseparable and by definition will remain so for as long as existence exists, why not call it ‘oneness’ and escape the paradox?

To summarize, Cartesian Dualism is no longer a useful model due to quantum mechanics revealing that analysing any apparent mind-body distinction cannot explain what is going on. Quantum mechanics tells us that the only thing that is ever experienced, the only the that ever exists, is the interaction between the ‘us’ and the ‘it’, or according to Heisenburg; “between the idea of an event, and the actual event” (Heisenburg 1958) (as cited by Zukav 2001, 66). Deciding whether one should refer to this as a form of dualism or ‘oneness’ seems like a semantic quibble, but my point has been made. Dualism carries all sorts of Cartesian connotations that imply we experience both a mental and physical realm, when actually they are the same thing. This brings me onto Gilbet Ryle’s (1949) objection to Descartes because my conclusion sounds startlingly similar to his, but is in fact the opposite.

Ryle’s objection to Descartes

The above section explains what I believe to be the origin of what Ryle describes as Descartes, “category mistake” (Ryle 1949) (as cited by Chalmers 2002, 32). Ryle says Descartes separated the soul from the body due to his religious beliefs not allowing for there to only be mechanical processes, of which the soul or mind is but one of. Ryle may well be correct about the motivation behind Descartes’ thought process, but as demonstrated he is disastrously wrong claiming the mind to be only a cog in the “great machine” (Ryle 1949) (as cited by Chalmers 2002, 37). This is not only because of his categorization of the mind, but in describing the Universe as a ‘great machine’, an inherently physical, materialist description. Ryle may be right escaping from dualism into ‘oneness’ but he has missed the bigger picture by trying to squash reality into Newtonian science, which has very limited usefulness.

In my view, Descartes attempts the impossible task of blending his religious beliefs with Newtonian science. This is impossible because all religion, regardless of its many highly debateable aspects, includes a simple wisdom that people are important - much more important than the miniscule value given to them by Newtonian science. With quantum mechanics personal experience is given an almost sacred value. We do not experience a tiny part of a pre-existing external world, we only experience our interaction with it and that interaction creates existence – that interaction is existence. It is a tragic irony that after millennia scientists are reaching the same conclusion as the Buddists and other Eastern religions did. There is only a oneness, a oneness of consciousness.


1. What about other varieties of dualism? Are they all undermined by this?

2. This greater understanding is not useful in practice and so is not a good theory – because it lacks usefulness.

In answer to objection one I shall examine the Thomas Huxley’s views on consciousness and how it relates to whatever else it is that he thinks there is. He says that it is impossible to prove the presence or absence of consciousness in anything other than your own brain (Huxley 1874) (as cited by Chalmers 2002 26-30). In his view consciousness is a bi-product of the mechanical processes of the brain and nervous system. He reaches this conclusion due to experiments on both frogs and people in which brains are either damaged or almost completely removed (in the case of the frog). The brain-damaged subjects have an amazing ability to continue as if they were not damaged. The frog swims when dropped in water, swallows when fed and avoids jumping into obstacles when tickled despite appearing to be blind. The man, a brain damaged French solder, has brief phases of mental abnormality. During these abnormal phases he can dress himself, smoke, eat, walk about and generally function very normally unless put in a new environment in which case he walks into things and changes direction when pressured without any resistance. He does not react to pain either in his abnormal state, but will eat avidly food offered to him.

Huxley says the stimuli of the nervous system cause the state of consciousness and that the molecular changes in the brain are the causes of the states of consciousness. He says that although a person’s consciousness may be more intense than a non-human animal’s and consisting of sentences as well as feelings, it is a mere by-product of the mechanical process and has no impact on our lives at all. He concludes therefore that people and other animals are conscious automata.

On the question of whether an individual has a soul Huxley says no; if we did it would be like saying the bell on a clock is the soul and its chime causes the works to go round. He concludes that the results of this are fatalism, materialism and atheism.

This is clearly not compatible with my proposed theory. In Huxley’s dualism there are mechanical processes and there is a bi-product, consciousness. In my theory, there is only one ‘thing’. It can be called consciousness, or it can be called experience, or it can be called interaction, or it can be called ‘one soul’, or simply ‘onesness’, or even, dare I say it, it can be called ‘God’. That is it. There may be mechanical processes, which are a bi-product - or an illusion - created by consciousness, but as I have shown these mechanical processes are not Universal, they do not apply in the sub-atomic realm and the sub-atomic realm appears to be conscious itself. The sub-atomic realm encompasses and contains within it the Newtonian mechanical realm in which Huxley’s theory of conscious automata resides.

What does this mean regarding its truth or falsehood? Nothing, the best a theory can hope for is to be useful, not true. When something is deemed scientifically ‘true’ it is only really saying that it is ‘useful’ and works within a tested model. Newtonian physics is useful, but not ‘true’. It does not work with sub-atomic particles or consciousness. Quantum mechanics does. Huxley’s description of consciousness does not make sense. Why would there be a bi-product? Especially a bi-product that appears to increase with time as the automata become more sophisticated? He could have just as easily concluded from his experiment that consciousness is not limited to the brain. He could have concluded that the brain is a manifestation of an intensity of consciousness. Nevertheless calling consciousness a bi-product is a backhanded dismissal of something he cannot explain with his theory.

In answer to objection two I risk irrelevancy, but I can simply say that the baffling irrational nature of quantum mechanics serves as a humbling device; encouraging people to trust neither their own judgement nor another’s, no matter their societal or military decoration, of which the positive utilitarian consequences of holding such an attitude are huge.


Consciousness cannot be explained on the macro-scale. It is the fundamental issue in dualism to find out how consciousness fits with the physical reality we experience. Are there both or is there one, and if there one, is it physical in nature or not? Trying to understand consciousness with Newtonian science is like trying to understand how cells function without a microscope. You can theorize and theorize and theorize, but until you have a look and zoom in you cannot know. One final illustration here will mark the death of dualism.

There is a scientist trying to explain consciousness. He has a feeling it is important, but when asked he cannot prove it with his naked eye. He has two courses of action:

1. Become a mystic and renounce conventional rational reasoning. 2. Build a microscope to see if he can find it by looking more closely.

He is asked again, ‘have you found consciousness?’ Regretfully, he says no, not yet, just cells and fibres and beautiful organic patterns. Again he has two courses of action:

1. Decide that he was mistaken in believing in the importance of consciousness and reach the conclusions Huxley reached, namely fatalism, materialism and atheism. 2. Continue building increasingly powerful microscopes to look at reality even more closely.

After numerous repetitions spanning the entire advancement of science he is asked again; ‘have you found consciousness?’ This time there is only one course of action. He must reply:

“Yes. It is everywhere. It is the only thing there is.”


Bohr, N. (1958) Atomic Theory and Human Knowledge, New York: John Wiley

Chalmers, D. (2002) Philosophy of mind classical and contemporary readings, New York: Oxford University Press

Cottingham, J. and Stoothoff, R. and Murdoch, D. (trans) (1996) The Philosophical writings of Descartes, Cambridge University Press in Chalmers, D. (2002, 22) Philosophy of mind classical and contemporary readings, New York: Oxford University Press

Cottingham, J (trans) (1985) Meditations on First Philosophy by Rene Descartes, Cambridge University Press in Chalmers, D. (2002, 11) Philosophy of mind classical and contemporary readings, New York: Oxford University Press

Heisenberg, W. (1958) Physics and Philosophy, New York: Harper and Row

Huxley, T. (1874) Fortnightly Review in Chalmers, D. (2002 26-30) Philosophy of mind classical and contemporary readings, New York: Oxford University Press

Physical reality: photons in two places at once. Oracle Education Foundation consulted 10.11.10 <http://library.thinkquest.org/C008537/cool/diffraction/diffraction.html>

Quantum Mechanics. Wikipedia consulted 10.11.10 <http://en.wikipedia.org/wiki/Quantum_mechanics>

Ryle, G. (1949) The concept of mind, Hutchinson in Chalmers, D. (2002, 32 and 37) Philosophy of mind classical and contemporary readings, New York: Oxford University Press

Zukav, G. (2001) The dancing wu li masters, New York: Bantam Books


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