In his Discourse on Method and Meditations on First Philosophy, René Descartes says that he knows clearly and distinctly that he exists as a thinking thing, res cogitans, but he is not certain that he exists as a bodily thing, res extensa, and because he can distinguish between his mind and his body, the two must be separate and distinct. These entities work together: the body sends the mind information about this world; the mind processes information and makes decisions, and the body follows the mind’s instructions. In this paper, I will show that Descartes’s theory is strong, if not flawless, and I will discuss its moral implications. First, I will detail two particular strengths of Descartes’s argument: (1) it provides an adequate solution to his “evil god” thought experiment, and (2) it explains the physical phenomenon of the near-death experience. Second, I will answer three arguments against Descartes: (1) a truth, such as the oneness of mind and body, can be true even if I am able to doubt it; (2) recent scientific discoveries indicate that the mind is corporeal and subject to the laws of cause and effect, and (3) it is impossible to prove the existence of an incorporeal mind, so we shouldn’t fool ourselves by believing in such a thing. Finally, I will discuss the differences between dualism, which is Descartes’s theory, and materialism, the main rival to dualism, relating to metaphysics, epistemology, and ethics, and I will argue that these differences strengthen the case of dualism.
Methodic doubt, which is the refusal to believe anything in which one cannot have absolute certainty, is the vehicle for Descartes’s philosophy. Descartes argues that he cannot trust his senses because there might be an evil god who is deceiving him. Because this god is either omnipotent or extremely technically advanced, he could construct an entire world which seems to exist but does not. I might believe that I am at Duke University in 2004, but the god could really be harvesting me for electricity inside his home in the year 3000. Having successfully destroyed man’s certainty in the physical world, Descartes turns his attention to the mind: is he really a thinking thing, or is this, too, an illusion? He realizes that the existence of his mind is axiomatic; because he is thinking about his mind’s existence, he must exist as a thinking thing. The evil god may have fabricated my body, but he cannot fabricate my mind; I have it, and I am thinking. Thus, my mind and body are separate.
Materialism, the chief rival of dualism, views the mind and body as one substance, so the existence of my mind necessitates the existence of my body, and I can and must trust my senses. This explanation is satisfactory only if the evil god does not exist. If he does, then the materialists are being fooled. Dualism can address the evil god, and materialism cannot. Thus, dualism has the advantage.
Many people, after suffering traumatic physical experiences such as car accidents or strokes, recall leaving their bodies, impartially observing these now-empty shells for a time, and then returning and restoring life to them. These accounts, called near-death experiences, coincide perfectly with dualism, which says that the body can perish, but the mind (also known as the soul) cannot, and at death, the two separate. Materialists cannot accept the reality of a near-death experience, so they have two responses for a person who claims one: he is lying, or he is hallucinating. I reject the first because people who claim these experiences, including my father, have proven themselves trustworthy in all other aspects of their lives and would not break character for fifteen minutes of fame. The second response, while impossible to reject, is nevertheless difficult to accept. It seems unlikely that a person who is near death would have mental faculties powerful enough to construct an artificial experience which feels completely real and which coincides perfectly with dualism. It seems even more unlikely that multiple people would report the same experience. If these witnesses are hallucinating, then they call into question the amount of trust we can place in our senses; this, too, lends strength to dualism. For a theory to be true, it must prove true in all possible cases. Descartes’s theory proves true in the case of near-death experiences, while its rivals’ explanation of them is tenuous, so the argument for dualism is strong.
I will now address three objections to dualism. The first calls into question Descartes’s assumption that the mind and body are separate and distinct things because one can doubt the body’s existence, but one cannot doubt the mind’s existence. These critics say that something may be true even if one doubts that it is true; for example, a child may doubt that the interior angles of a triangle add up to 180 degrees, but as the rest of us know, this mathematical principle is completely certain.
This is a sound objection to Descartes’s theory. It does not disprove dualism, but it does show that dualism is not necessarily true. I can doubt that my mind and body are one, but it is possible that they really are one, and I simply do not have enough information. Nor can I imagine a scientific discovery that would prove materialism and disprove dualism. Either theory could be true, so I must choose one or the other based upon induction, not deduction.
The second objection comes from the emerging field of neuroscience. Neuroscientists claim that all human actions and emotions can be traced to the brain, and everything we think, feel, or do results from a series of cause-and-effect relationships within this organ. Our minds are corporeal and extended; they are no essentially no different from our lungs or our veins.
The neuroscientists’ claim fails for two reasons. First of all, this field is embryonic; what we know about the brain is insignificant compared to what we do not know. We know the parts of the brain where colors and emotions register, but we still have no understanding of higher-level thinking. Furthermore, their argument suffers from the problem of “Correlation VS Causation.” We know that certain emotions are linked to the release of certain chemicals in the brain, but we do not know if the mind triggers the emotions and orders the release of chemicals, or if the chemicals from the brain affect the actions of the mind. It is possible that the activity we observe in the brain is the result of the actions of the incorporeal mind. This situation would be consistent with dualism.
Finally, critics say that it is impossible for us to scientifically prove the existence of an incorporeal mind, so any reasonable person would disavow this genie rather than believing in it. The problem with this argument is that no one has satisfactorily disproved dualism, and none of the alternatives to it are superior. A better attitude would be “if it ain’t broke, don’t fix it.” There is much in this world that we do not understand, and so there is no reason to denigrate anyone who believes in a supernatural dimension. If the dualist is correct, then it is the materialist who is blinding himself from reality.
The differences between dualism and materialism are not limited to the mind-body problem; they extend throughout metaphysics, epistemology, and ethics. The mind-body problem is closely related with the metaphysical problem of free will. According to Descartes, because the mind is independent of the body, man has absolute free will. He can decide to do whatever he likes, even if he cannot always carry out his decisions; he cannot fly, but he can choose to attempt it. Thus, man’s faculty of volition is free of cause and effect. He is an “unmoved mover” of sorts. God, too, is an unmoved mover in the dualist metaphysics. He is incorporeal, and he created the world from nothing, violating the law of cause and effect. Man can choose whatever he likes, and God can do whatever he likes.
The materialist, meanwhile, is a determinist, which means he rejects free will. Because the mind is completely enclosed within the brain, and because the brain is a physical faculty which must obey the laws of cause and effect, every action that a person takes, and everything he thinks, results from a myriad of previous factors. Materialists, who reject the incorporeal mind, are also very likely to reject an incorporeal and omnipotent God.
Another interesting element of the dualist ethic is the potential for conflict between the body and the mind. The body has insatiable desires for wine, women, and song which the mind must regulate and control, as Dr. Jekyll had to contend with Mr. Hyde. Materialists provide a more unified view of human behavior. Since the body and mind are one, the possible conflict between them is as not as dramatic as the dualists convey.
The immortality of the soul is a centerpiece of Descartes’s theory. My body might die, but my spirit will live on forever. Thus, dualists are much more likely than materialists to subscribe to religions because they provide service for this immortal soul and help a man to ensure that he will spend his eternity in bliss, not in suffering. Dualists are more likely than materialists to become martyrs for a cause because dualists believe they will be ultimately rewarded in the afterlife while materialists have but one life to lose.
The dualist belief in the immortal soul also provides a compelling argument for the unique value of the individual human being. A person is partially corporeal and moral and partially otherworldly and immortal. Unlike plants and animals, he does not belong on earth; unlike angels, he resides there and experiences its beauty for a short time. Man is not more or less unique depending upon the uniqueness of his genes, and no one is replaceable. Dualists accept a transcendent moral code; it is written in the spiritual world, not the physical world, so it applies to all times and to all cultures. Men can receive knowledge on both the physical and the spiritual plane; divine revelation is possible, and if God is good, it is infallible. Dualists follow the example of Plato, seeking the good while in this world and hoping to fully experience it in the next.
Materialists also believe in the value of human beings. They have a different reason: whereas dualists appreciate human life because it has eternal value, materialists appreciate human life because it is fleeting, and a person, once dead, will never live or breathe or think again. While dualists base their moral code upon the perfect ways of the other world, materialists make base their moral code on living well in this one. Moral laws are not metaphysically transcendent; they are similar throughout history because men and what is good for them have been similar throughout history. Materialists act morally because they see that they are happiest when they do so. Men receive all their knowledge from senses and reason, and there is no such thing as divine intervention or revelation. Some materialists, such as Nietzsche, despair at the brevity of life, but most wish merely to make the best of the time they have.
The ethical systems of both the dualists and the materialists are plausible, and if I met a person who practiced either of them well, I would admire him. Nevertheless, I must give the advantage to dualism. Dualism provides much more hope for men than does its rival. Its justification for acting morally is stronger because its moral authority, an all-powerful God, is much stronger. I feel that its portrayal of ethics as a struggle between spirit and flesh is quite plausible. Also, I have experienced many things in my life, including divine revelation, miracles, and the testimony of my father on his near-death experience, which fit into the dualist’s worldview but not the materialist’s. Finally, I simply cannot imagine myself completely disappearing. I cannot remember how I became conscious, but now that I am, I feel like it would be truly impossible for me to return to my previous state of non-existence. The soul must be immortal.
Using the process of methodic doubt, Descartes rebuilt the foundations of philosophy. His theory of dualism has dominated Western culture ever since, and this is because it has great merit. Descartes’s theory explains the phenomena we experience in this world while parrying each attack on its logical and empirical foundations. It provides men a rational reason to hope for immortality and to try to achieve the good. Dualism will be a sound answer to the mind-body problem as long as men have both minds and bodies.