Property Dualism (A brief guide)

In this guide, we will discuss “Property Dualism”. We will mention what property dualism is, how it differs from substance dualism, property dualism and qualia and some of the most important arguments for property dualism.

Property Dualism

Property dualism theorists believe that ultimately, the reality is made of just one substance unlike substance dualists argue. This only substance is believed to be the physical but what substance dualists define as the mind is in fact non-physical properties of the physical properties. This means that our thoughts, ideas and consciousness are non-physical properties and they are not referred to as a different substance. The mental can in fact be reduced to physical properties according to property dualism. 

In other words, since the mental is a non-physical product of the physical brain, the neurons and the synapses allow the mental properties and so here is where the mind-body problem is. Subsequently, the world is just made up of the physical and the mind can be reduced to the physical. But the phenomena of mental properties is just down to the arrangement of the physical if matter is arranged in a precise and exact way mental properties will appear.

Let’s take the example of heat from Thomas Nagel and Saul Kripke into consideration. We feel the sensation of heat as a non-physical property but this is reduced to kinetic molecular energy. Since heat is the non-physical sensation we get to feel coming from the physical molecular motion, it could be useful to understand that mental ideas normally come about through physical changes. 

Another example is the pain you could feel because you cut your arm and we could indicate that there seems to be a difference between mind and body. 

Property dualism and qualia

Property dualism defends that the brain is the only thing that ‘really matters’ but the brain might have two different kinds of properties. One is referred to as the ‘physical property’ so we could see it in the physical properties of the brain such as the weight, shape, colour, etc., and those properties it reduces to the weights of the individual components that ultimately are the parts that make up the brain. 

However, there are other properties that the brain can have such as feeling pain, which is said to be reduced to the parts that compose the brain like the electrons, neutrons and protons, and the interaction between them and other substances.

Property dualists say that there is something called qualia or the qualia associated with having painful experiences, which instead of reducing this to the physical components of the brain, it is said to be irreducibly mental. When talking about qualia we refer to non-physical properties but physicalists would argue that there is no such thing as qualia or qualia somehow can be reduced to brain properties.

Do we have qualia?

Let’s start by defining qualia, accordion got The New Oxford American Dictionary it is defined as:

“The internal and subjective components of sense perceptions, arising from stimulations of the senses by phenomena”. For some people, qualia can be translated into qualities/properties and those qualities/properties are supposed to be the qualities of the mind.

If we analyze the definition more in-depth, we would find two terms that can be considered important when understanding what qualia is. Those terms are ‘internal’ and ‘subjective’. In other words, qualia are the ways things seem to the senses (subjective), as opposed to the ways things really are (objective).

For instance, two people could be observing the same object but their experience would be subjective. For one of them, the object could have a different colour than the one reported by the other, even though it is the same object. Some philosophers may argue that qualia are in your mind and that would explain the subjective and individual experience.

Property dualism vs Substance dualism

Property dualism claims that the universe is composed of two very distinct properties. Most of the universe is filled with physical properties but when we get to the mind, especially when we talk about qualia, property dualists argue that this is a property that can’t be reduced to any physical properties.

In contrast, substance dualists claim that a substance is characterized by its properties but they talk in terms of ‘things’, the thing which possesses such properties. The mind in this case becomes an immaterial substance over and above any immaterial states. 

Arguments for property dualism

Here are the most important arguments for property dualism.

Knowledge Argument

Thomas Nagel published his work back in the 70s called ‘What is it like to be a bat?’. At first, you may think it is a weird title and why on earth would he focus on bats. Bats are very interesting creatures because even if they lack eyesight, they have the sonar to navigate and locate things, which makes it fascinating. However, we are all organisms and we are somehow (distantly) related so we could have similar experiences.

Moreover, we have the knowledge argument explained through Jackson and what he proposes as ‘Mary’s room – Mary the super-scientist’. If you would like to know the more of the story you can find it online but for the argument, we will just mention how, even if mary knows everything there is to know about the brain, as soon as she walks out the room (where she only experienced what it is like to see in black and white) she sees the colour red for the first time.

The argument here against physicalism and in favour of property dualism is how before Mary leaves the room, she doesn’t know what it’s like to see red or have that red experience. However, before she left the room, she already knew everything physical, she knew all the relevant facts. If she learns something new, which is the experience of seeing red, then red qualia must be something non-physical. 

As indicated on, “The knowledge argument aims to establish that conscious experience involves non-physical properties. It rests on the idea that someone who has complete physical knowledge about another conscious being might yet lack knowledge about how it feels to have the experiences of that being.”

The Modal Argument

Unlike the previous argument, here we don’t talk about knowledge. Instead, we talk about modality, which in philosophy is the study of possibility and necessity. Here we will talk about what is conceivable and inconceivable concerning qualia, so we are going to be thinking about some scenarios and analyzing them through the modal argument.

There are two different scenarios or experiments we could talk about (conceivable scenarios) even though if you think about them, they seem inconceivable. Let’s start with something called the ‘inverted spectrum’. The argument here is that there could be (hypothetically) two individuals that are the same in all physical aspects aside from, let’s say, their spatial location (two different places).

However, even if they are physically identical or alike, when they stare at an apple or a banana, the way the banana looks for one of them, their subjective qualia when looking at the apple or banana is the exact opposite of what the other individual is looking at. 

Subsequently, the question is: isn’t it conceivable that even if they are physically the same, the subjective experience of one of them is the opposite as the subjective experience of the other one? Well, according to the argument, if spectrum inversions are possible then property dualism is true and if something is conceivable, then it is possible. Since spectrum inversions are conceivable, property dualism is true.

Why is this blog about Property Dualism important?

As we have discussed when talking about property dualism, we have come to understand how they believe there is the only substance, contrary to what substance dualists argue, this means that our thoughts, ideas and consciousness are non-physical properties and they are not referred to as a different substance. The mental can be reduced to physical properties according to property dualism. 

Property dualists talk about a concept called qualia which may seem a bit difficult to grasp because when talking about qualia we refer to non-physical properties but physicalists would argue that there is no such thing as qualia or qualia somehow can be reduced to brain properties. Finally, we talked about the arguments in favour of property dualism that are worth mentioning and analyzing more in-depth. 

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Frequently Asked Questions (FAQs) about Property Dualism

What is the difference between substance dualism and property dualism?

Philosophers and thinkers that consider themselves as substance dualists claim that the mind/soul is a separate identity than the body or physical property of the human being that will live on past the deterioration of the body. Property dualism claims that the mind, which is different from the physical human frame, is still linked and thus will end when we die.

What is the relation between mind and body according to substance dualism?

According to dualists, the mind or the soul is composed of a non-physical substance, while the body is considered a physical substance is known as matter. According to many substance dualists, mind and body can affect one another. This form of substance dualism is also known as interactionism.

Is the mind a material?

The mind is considered by most as an immaterial entity since there is no place where we can locate it. However, some philosophers and thinkers have associated the mind with the brain but it is a much more sophisticated emergent property that doesn’t really have a shape. Since the mind can’t be measured or extracted, it is considered immaterial.

Are mind and body separate?

Many have considered the mind and body as separate entities that are however linked and have an effect on each other. As human beings, we have the mind, as a non-physical entity or property and the body (brain) as a physical entity. This is what many dualists argue, being two substances that exist independent from each other or in other words separate. However, as Descartes argues, there is a two-way interaction between the mental and the physical substance.

What is non-dualistic thinking?

Non-dualistic thinking also known as non-duality means ‘not two’ or ‘one undivided without a second’. Non-dualists usually believe that there is a mature state of consciousness, in which the dichotomy of I-other is “transcended”, and awareness is described as “centerless” and “without dichotomies”.

References (Pete Mandik): “24 – Property Dualism and Qualia”