According to the concept of Cartesian substance dualism, humans are consistent f two substances, namely; a body, and the other a person (mind). Descartes explains that the “person” element is not a purely mental substance. This means that it cannot be described in terms of consciousness and or thought separate from all other elements. However, persons and their bodies are both substances and possess unique identity conditions. Since the two, body and person (mind), are essentials of what constitutes a human being, then the concept qualifies as a form of substance dualism known as Cartesian substance dualism. Remember that dualism is the idea that the body and the mind are unique entities, each of which exists isolate and identifiable from one another. Under the concept of Cartesian dualism, the mind and body substances engage in a two-way interaction forming a functional unit which is responsible for human experiences.
Nature of the Mind According to Cartesian Substance Dualism
As Descartes explains, the mind is a “thinking thing [res cogitas]” as well as an immaterial substance. In line with the Cartesian substance dualism concept, the mind can exist without a body as a complete and functional entity. This implies that the mind is an identifiable entity that exists on its own. The mind is also an immaterial substance. An immaterial substance is more “spiritual”, “abstract”, or non-physical in nature. It is a metaphysical substance. A substance, as Descartes defines it is a thing which can exist on its own, and its existence is not dependent on something or anything else.
Princess Elisabeth’s Objection to Cartesian Substance Dualism
After Descartes’s theory became well known in the philosophy circle, Princess Elisabeth wrote a letter to him, in which she doubted Descartes’s theory by raising the interaction problem. To explain it in detail, Princess Elisabeth wanted to know, if Cartesian Substance Dualism is true, namely immaterial mind and material body are two different existences, then how can an immaterial mind cause anything in a material body, and vice versa? Her concerns were based on causation, whereby a person’s thoughts can cause them to move their body.
An example of this is when someone sees a McDonalds, and they feel the desire to have a “Big Mac”. The person then puts one foot in front of the other, and soon they are standing in the queue ready to order and eat a “Big Mac”. If the mind and body were two isolate entities, then it would be difficult for the mind to cause movement in the body resulting in physical actions. Princess Elizabeth’s concerns are both reasonable and legitimate as they pose a philosophical dilemma. In my opinion, I find that this objection has its point because Descartes addresses that mind and body are two different substances with different properties; thus it is difficult for him to explain how an immaterial mind can lead to the action of a material body. In addition, if Cartesian Substance Dualism is accurate, under the condition that mind is an immaterial substance, how come that an individual’s mind can only lead to the action of this individual’s body instead of another’s body? Therefore, the connection between mind and body tends to be closer than Descartes claimed it to be.