Dualism (philosophy of mind)

In philosophy, dualism (philosophy of mind) is the belief that the mind and body are separate. The mind is a creation of the brain and is intangible, while the brain is made of physical matter and is tangible. Dualism has a long history, dating back to Greek philosopher Plato, and it continues to be debated into the twenty-first century.

Background

Plato was the first to explore the relationship between the mind, or the spirit, and the body. In the philosopher's view, the soul was contained within the body during an individual's lifetime and was only free after death. The knowledge possessed by the soul is beyond ordinary human knowledge. Only in death, when the soul is released from the body, does this knowledge become clear.

Plato supported his argument in a number of ways. He stated that humans possess certain innate ideas, such as the idea that some objects may be larger or smaller than others, as inarguable truths. He argued that one entity often grows out of its opposite, such as life may come from nonlife or rain may fall where it was previously dry. In the same way, the soul, a nonmaterial entity, comes from the body, which is a material entity. Plato also argued that part of the reason human life ends is because the body is a combination of more than one entity. He believed that things that exist in more than one part can break down more easily than things that are self-contained. He introduced these ideas in a work called Phaedo.

French philosopher René Descartes wrote at great length about dualism in the seventeenth century. He believed that the ability to think was the key characteristic of human life. He distinguished between the mind and body in a different way. Descartes believed the mind thinks but has no properties that can be measured (such as weight or size), while the body has properties that are measurable but cannot think. He believed that the mind and body were joined together in the soul, which he located in the pineal gland of the brain.

Descartes elaborated on this distinction in several ways. One supporting argument concerned divisibility. He reasoned that the mind and body must be different from each other because the body can be divided into physical parts, but the mind cannot be divided physically. He also supported his approach to dualism with an argument about doubt. Descartes believed that the body should be doubted, meaning that a person could never be sure of how the body would react to different stimuli, how long it would survive, or whether it would become sick. The mind, on the other hand, was consistent—the statement "I think, therefore I am" correlates directly to this argument. The only thing a person can be entirely sure of is that one is thinking; however, even the idea of being "sure of" something is just an idea.

Additionally, Descartes posed the argument: Because a person can imagine the mind separate from the body, the two things must be separate in reality as well. If the mind can exist separately from the body and is not dependent on any of its organs for functioning, this confirms the division between the two.

Modern Responses

In the centuries following Descartes, numerous related arguments and counterarguments have arisen concerning dualism. Many of these use the indiscernibles principle, sometimes called Leibniz's law. It states that a person can only call two objects or entities identical if the objects always have all the same properties at the same time. This would mean that the mind and body are not the same, since they do not possess the same properties.

The mind could be said to possess no properties—at least none recognizable by physical investigation. For instance, some philosophers argue that because the mind's thoughts can only be known by the person thinking and are thus private, the mind can be distinguished from the brain, whose activities can be measured by scientific equipment, experiments, and observation.

Another argument suggests that the difference between the mind and the body is dependent on whether a person can say ideas are true or false. A person may believe the sky is beautiful, but that belief cannot be said to be true or false—it cannot be physically proven. Because the brain's actions are entirely chemical and physical, they can be evaluated as response to stimuli, while the mind's actions cannot be impartially examined.

Another argument based on the idea of intentions, or things we want to do, also exists. A person might intend to run across the street to meet a friend, but that intention is a feeling; it is not physically measurable in its intensity. The brain cannot have an intention because the brain is a physical mass subject to physical limitations and changes.

Certain schools of thought claim that the ability to have free will, or be in control of one's actions, is a sign that the mind and the body are separate. The brain by itself does nothing; the mind tells the brain, and the brain then tells the body what to do. Some philosophers also believe that although a person can vocalize a thought, such as "I need a new hat," this thought may be a property of the brain. This phenomenon is caused by an interaction between the organ and different neural networks. A person cannot say that same thought is a property of the mind because the mind is not something known to have properties.

Bibliography

Calef, Scott. "Dualism and Mind." Internet Encyclopedia of Philosophy. Internet Encyclopedia of Philosophy. Web. 2 Sept. 2015. http://www.iep.utm.edu/dualism/

Pecorino, Philip A. "Chapter 6: The Mind-Body Problem. Section 3: Dualism." Department of Social Sciences, Queensborough Community College. City University of New York. Web. 2 Sept. 2015. http://www.qcc.cuny.edu/SocialSciences/ppecorino/INTRO‗TEXT/Chapter%206%20Mind-Body/DUALISM.htm

Robinson, Howard. "Dualism." Stanford Encyclopedia of Philosophy. Stanford University. Web. 2 Sept. 2015. http://plato.stanford.edu/entries/dualism/

Skirry, Justin. "René Descartes: The Mind-Body Distinction." Internet Encyclopedia of Philosophy. Internet Encyclopedia of Philosophy. Web. 2 Sept. 2015. http://www.iep.utm.edu/descmind/