A note on property dualism

Introduction

Dualism is a philosophical concept concerning the nature of substances, objects, and entities around us trying to explain how these entities interact in the chain of causation. Dualism is contrasted with monism, meaning there is only one fundamental kind, category of a thing or principle, and pluralism, which states that there are multiple categories of things [1]. In the Philosophy of Mind, Dualism as a theory aims to explain the nature of our thought and actions and how the mind and the body are different from each other. One early view of Dualism, called Substance dualism, was put forward by Descartes and it came to be known as Cartesian Dualism. According to substance dualists, the mind and the body, i.e. the physical and the mental, are completely different “substances” and are capable of independent existence. The physical is something that can be observed, seen, touched, divided, and so on. The mental/mind on the other hand is our ideas, thoughts, consciousness, and so on [2]. This view is similar to religious concept of the soul and the immaterial. One of the biggest criticisms of this theory is that it is not able to explain how the non-physical came into existence and how these two different substances are able to interact with each other causally. One very interesting idea that came out of this is that of Property Dualism which suggests that all substances and objects in the world are just physical. However, it is not necessary that physical substances only have physical properties. Physical substances can have properties that are both physical and non-physical(mental). The mental properties are irreducible to physical properties and therefore they are not the same as brain states. [3] This essentially means that the mental is just a non-physical product of the physical brain. This was explained by Kripke[4] and Nagel[5] using an example. They said that when we stand in front of a bonfire, we experience warmth which is a non-physical mental property. But this property can be reduced to the increased molecular kinetic energy in our body due to high temperature leading to a feeling of warmth. Hence the warmth is a mental property arising from the physical substance that is our body.

In the rest of the article, I sought to present and analyse some of the best arguments for Property Dualism. To do this, I employ a technique called steelmanning which means to present the argument that you are are critiquing in its best and strongest form. This is completely opposite of a strawman. So, after steelmanning an argument, I go on to present my own commentary over the argument as to why I think that argument is correct or false.

Property Dualism explained

In his essay titled “Why I am not a property dualist” John Searle presented the best and most precise version of the assertions of property dualism. According to him, there are two metaphysical states of reality, the physical and the mental. The physical is the observable objective phenomena, and the mental is the subjective first-person experiences. As mentioned in the introduction, mental properties are irreducible to brain states and therefore, they are different from each other and form a dualist paradigm as opposed to the materialist view. However, the mental properties are not separate objects, but rather features and properties arising from the physical realm itself as explained above using the heat sensation example. [6]

The problem of causality

The previous paragraph is one of the strongest steelmans of the argument. As mentioned in the introduction, one of the biggest criticisms of substance dualism was its inability to explain the interaction between the mind and the body as separate objects. The property dualism too runs into some kind of a problem in this context. How are the physical and mental properties able to influence each other? One answer to this question is given by an idea called epiphenomenalism according to which the mental properties are just epiphenomenal, i.e. they are contingent on the physical environment and that they can not cause physical phenomenon. Taking this argument forward, this would mean that the physical universe is causally closed and that the mental properties have no influence whatsoever on it. Our thoughts, our ideas, our subjective experiences, are all just a consequence of the different arrangements and motion of the physical particles constituting the universe. Our mental states are simply a debris of evolutionary development of the mind. For example, there is no conception of temperature at the level of a single particle. However, when a group of particles come together and interact, move, and collide, they give rise to temperature as the emergent property of the collection of particles. Similarly, our mental properties are just a consequence of our neuronal arrangements, activation, synapses, and so on. Hence this view completely goes against the distinctness of the mental properties, which is the backbone of dualism. This view is very similar to that of materialism. Therefore, epiphenomenalism is incompatible with property dualism. [8]

Another possible way to explain the causal relationship between the physical and the mental is to allow for the fact that mental properties can cause physical phenomenon. This means that if we consider an action of heating food, this is caused by our mental state of hunger. However, another completely physical explanation for this action is that a particular arrangement of neurons in our brain, specifically in the frontal lobe, causes the muscles of our body to perform this action of heating food. Now going by the postulates of property dualism, these two mental and physical explanations are irreducible to each other leading to a contradiction in the causal chain of events. Hence, this view is also not compatible with property dualism. [6]

Chalmer’s Phenomenology

David Chalmer was one of the biggest proponents of property dualism. He proclaimed that we know that there are properties of individuals (phenomenal properties) that are ontologically independent of physical properties. He identifies certain qualitative properties of subjective experiences and said that these phenomenal states are different from the neurobiological aspect of the mind, for example, the feeling of butterflies in the stomach, or the feeling of love. He says that such properties are “supervenient” to the physical properties and hence property dualism holds. [7]

This argument, although is able to provide a further distinction between the physical and the mental, still bears the problem of inconsequence of the supervenience of the mental properties. It is still not able to explain how the mental state of butterflies in stomach is able to influence and physical phenomenon. This is also unable to explain the origin of the property in the first place. It simply regards that there are certain properties that are unexplained by the normal causal chain, hence it spirals into the same problem as those of epiphenomenalism as those explained in the previous section.

Conclusion

This article presented idea of property dualism and tried to analyse its arguments from different perspectives. Property dualism does try to rectify certain radical implications of other dualistic frameworks but goes into some contradictions of its own. Going back to the original question of explaining the mind, is this distinction between the mental and the physical phenomenon actually useful/fruitful in any way? Is our current knowledge of biology not able to explain some properties?

References

[1] Robinson, Howard, “Dualism”, The Stanford Encyclopedia of Philosophy (Fall 2020 Edition), Edward N. Zalta (ed.), URL = https://plato.stanford.edu/archives/fall2020/entries/dualism/

[2] Vintiadis, Elly. 2013. “Emergence.” In Internet Encyclopedia of Philosophy, URL = https://www.iep.utm.edu/emergenc/

[3] Calef, S. “Dualism and Mind.” In Internet Encyclopedia of Philosophy, URL = https://iep.utm.edu/dualism/

[4] Malcolm, N. 1980. “Kripke on Heat and Sensations of Heat.” URL = https://doi.org/10.1111/j.1467-9205.1980.tb00409.x

[5] Ney, A. “Reductionism.” In Internet Encyclopedia of Philosophy, URL = https://iep.utm.edu/red-ism/

[6] Searle, John R. (2002). “Why I am not a property dualist.” Journal of Consciousness Studies 9 (12):57–64.

[7] Bratcher, D. “David Chalmers’ Arguments for “Property Dualism”.” In Philosophy Today, URL = https://www.questia.com/library/journal/1P3-45509980/david-chalmers-arguments-for-property-dualism

[8] Robinson, William, “Epiphenomenalism”, The Stanford Encyclopedia of Philosophy (Summer 2019 Edition), Edward N. Zalta (ed.), URL = <https://plato.stanford.edu/archives/sum2019/entries/epiphenomenalism/>