Aamenah Qutbuddin
December 1 2016
PHI 001 Professor Sennet
Section 6 Ceth Lightfield
The human mind is a complex idea that has always been a difficult notion to describe in terms of a definition or set of conditions. According to the theory of dualism, the mind and the body are two distinct, separate things. However, in contrast, an identity theorist would state that a human being is merely a physical entity, made up of physical substances. In this paper, I will give an argument using Leibniz’s law of identity for the dualist claim that mental states are distinct from physical states, and I will explore a rebuttal an identity theorist could use to object to the dualist argument.
According to Leibniz’s law of identity, if two things are identical (the same), they must share exactly the same properties. For example, if X is identical to Y, X must share exactly the same properties as Y. If they are the same, than any property that X has, Y has. Therefore, we can conclude that if there is even one property that X has and Y doesn’t have, or vice versa, X and Y are not identical i.e. they are not the same thing. Because of this notion of sameness, where in order for to things to be the same they have to share all of the same properties, we can conclude that mental states are distinct from, or not the same as, physical states.
According to Descartes, he could doubt that his body existed, but he could not doubt that his mind or thoughts existed. He could have even some sliver of doubt whether or not he had a body, because of the possibility that he was simply dreaming of having a body. When dreaming, it is often difficult to distinguish the dream from reality, and there is no guaranteed way to be certain whether you are dreaming or not. Or, he also claimed that he could doubt the existence of his body (his physical states) due to the possibility that it was an illusion created by an evil demon. However, he could not doubt whether or not he had a mind, because he had thoughts. He famously stated, “I think, therefore I am”, asserting that thinking implies a thinker. Since he had thoughts, he came to the conclusion that there had to be something, albeit intangible, having thoughts. Therefore, since he could doubt his body but not conceivably doubt his mind, he concluded that the mind and the body have different properties and are thereby cannot be the same thing. The mind and the body are not identical, and the mind is nonphysical and intangible. This leads to the idea that the mind is not part of the physical world, and occupies a different realm of existence.
The theory of dualism states the mind and the body are two distinct things. The mind is separate from the body, and it cannot be measured in any physical sense. Accordingly, mental states and physical states are distinct from each other. In the context of identity, if there is even one property of the mind that is not true of the body, or one property of the body that is not true of the mind, then the two cannot be identical, and therefore are not the same thing. Humans have both mental and physical properties, which are related but different. Physical properties are things that for example have weight, shape, color, size, etc. In contrast, mental properties cannot be measured, and are concepts such as beliefs, desires, emotions, character traits etc.
For example, if Alex believes that he is in Canada, it can be determined as true or false whether he is actually in Canada or not. However, his mental/nonphysical state of believing that he is Canada cannot be known as being true or false.
Although dualism seems to have a fairly strong argument for the mind body problem at first glance, there are also several objections for the claim that mental states are distinct from physical states. One of the dominant objections comes from physicalists, also known as identity theorists. Physicalism denies that mental states are nonphysical states. Physicalism is the idea that everything is physical, and nothing exists beyond the physical world. Identity theory states that when you experience something, it is reflected in a neurological state in the brain. Different parts of the brain correspond to different actions. For example, if Alex experiences pain, the feeling of pain is reflected in the corresponding brain state. So pain is simply a physical state represented by a particular brain state. Therefore, pain and brain state pain refer to essentially the same thing. Or if Alex has a thought, it is identical to some state of the brain. This theory claims that the mind and the brain are identical i.e. they are exactly the same thing.
Additionally, identity theory puts forth the idea of modes of presentation. Modes of presentation are different ways of referring, or presenting, the same thing. If the same thing can be known in two different ways, then it is possible for someone to know something under one mode of presentation, and not another. For example, Alex knows that Venus is a planet, and it is also the morning star. When someone refers to the morning star being a planet, Alex knows that they are referring to Venus, because he knows Venus under the mode of presentation that the morning star is a planet, and that planet is Venus. However, if someone says that “the evening star is a planet”, Alex would not know that the person is referring to Venus, because he does not associate Venus with that particular mode of presentation.
Since modes of presentation are different ways of referring to the same thing, the same concept can be applied to the mind body problem. Take the famous example of Mary and the color red put forth by Frank Jackson. His example states that suppose Mary is a scientist who is forced to look at the world from a black and white room through a black and white television. Then, suppose she is able to gain all the physical information there is to acquire about the color red. According to Jackson, when Mary is released from the black and white room and sees the color red for the first time, she gains new knowledge. Since she already possessed all the physical knowledge about the color red, but apparently gained new knowledge when she saw the color red that she could not have gained without actually experiencing the color, Jackson concluded that there has to be something more to have than just physical information. Although this thought experiment was intended to falsify physicalism, the idea of modes of presentation helps to counter this claim and further establish the theory of physicalism. Suppose that the physical concept of the color red and the mental concept of actually experiencing seeing the color red are simply different modes of presentation for the same thing: the color red. This leads to the assumption that physical and mental concepts are essentially the same thing, just under different modes of presentation. This undermines the dualist argument that the mind and the brain are two separate things.
Both dualism and physicalism or identity theory have various claims as to why they are correct. In summary, dualism claims that the mind and body are two distinct things, because they do not share all and exactly the same properties., which is a necessary condition in order for two things to be the same. However, identity theorists counter this by claiming that they are the same thing, they just seem different because they are under different modes of presentation. Neither theory is foolproof, and have both been subject to various criticisms throughout their history.