by Thomas Rauchenstein
Are human beings a duality of mind and matter, or are they simply physical beings? This question has been the subject of intense debate throughout the history of philosophy and is still talked about today. If the humans are no more than heaps of atoms, then how does one square this notion with issues like personal identity, life after death, human rationality, and morality? If a person is a mind that has a body, how do these two existents interact with each other? Is it possible, in this framework, to know other minds? It is evident that several positive and negative implications follow if a dualistic approach to reality is taken.
Some philosophers have argued that if human beings are substantial minds, then one cannot know if other minds exist because one only has access to other persons through physical interaction; this is the problem of Solipsism. Other individuals could very well be robots who express common human behaviors, but have no mind or self. Solipsism, be it true, would mean that minds never actually interact with each other, but suffer a lonely existence. Does this describe the way reality is? The fact that persons seem to interact with each other is hard to reconcile with dualistic thought.
By far, one of the most frequently cited problems with mind/body dualism is its inability to explain how the mind can interact with the body. The mind, by definition, is an immaterial substance that can exercise causal powers over the body. Some ask: "How could the soul, totally lacking in physical properties, cause things to happen in the body or visa versa?" (Habermas 44) This objection seems to imply that it is not reasonable to hold that X and Y are causally connected if one does not know how X and Y are causally connected. Unfortunately, for the physicalist, this objection has a weakness; scientists know that electrical fields interact with atoms, but have no idea how this interaction takes place. Further, the physicalist has not posited a criterion that determines how unlike X and Y must be before a causal connection becomes unlikely. One Dualist put it this way: "If the unlikeness of draughts and colds in the head does not prevent one from admitting a causal connection between the two, why should the unlikeness of volitions and voluntary [bodily] movements prevent one from holding that they are causally connected?" (Broad 98) Finally, it could be that the causal interaction between mind and body is direct and immediate, without any intervening mechanism (Habermas 45). In this case, the ‘how’ question of mind/body interaction is not applicable.
Apart from the problem of mind/body interactionism, substance dualism seems to have implications for how persons retain their individuality. Spatial locations cannot be ascribed to souls because they are non-physical entities; therefore, if souls are non-spatial, then how can one soul be distinguished from another? Dualistic thought requires that there be some sort of individuality to distinguish persons, but such becomes difficult if minds are non-spatial. Further, why is it that a soul only inhabits one body, rather than two, or three? The apparent loss of personal individuality has serious implications for the supporter of mind/body dualism.
The existence of substantial souls bears on the issue of person identity through change. Two fundamental views oppose the notion that persons remain the same over time: Physicalism and Epiphenomenalism. The former maintains that human beings are entirely creatures of matter. Epiphenomenalists are more dualistic in nature because they postulate the existence of mental properties; however, in this theory, the events at the physical level obey deterministic physical laws and mental events are mere byproducts (Moreland 98) Both physicalists and epiphenomenalists ultimately ground the self in material processes and, therefore, believe that humans really have no constant identity. On the contrary, substance dualism views the soul as an unchanging entity, even though the properties had by the soul are continually fluctuating; therefore, according to substance dualism, personhood endures from birth to death.
It seems that personal identity through change has significant implications on the issues like punishment and fear of the future. First, if human beings do not retain personal identity over time, then why should society punish anyone for crimes? "The self that committed the crime in the past is not literally the same self who is present at the time of punishment" (Habermas 37). In this case, every jail in the world holds innocent people who are being punished unjustly. Further, if selves do not continue into the future, then fear of the future must be an illusion. Only if it is possible to manipulate the future can one be anxious about what is to come. Substance dualism definitely makes sense of punishment and fear of the future.
Substance dualism also has some interesting implications for the issue of life after death. Many thinkers, notably Plato, have argued that the existence of the soul as a simple entity demonstrates that the self survives bodily death. Plato maintained that the soul must be immortal because there is no good reason to believe it can be decomposed or annihilated (Plato 60c). Thus, if Plato's argument is sound, dualistic theory lends supports to the reality of the afterlife. Further, substance dualism allows for one to retain his/her personal identity after the event of death. If physicalism is true, then the body faces extinction at death; for the physicalist to maintain some respectable belief in immortality, he/she may have to postulate that God recreates bodies after death; however, this scenario reduces persons to mere replications of their original selves. In other words, "[w]e are not interested in becoming extinct at death and having a double recreated who looks like us or has our memories or character traits. What we want to know is whether I myself will live on after the death of my body" (Moreland 51). This raises the question: who would desire an immortal existence that does not involve the same self? Dualistic thought answers this question by postulating that minds remain unchanged after physical mortality has occurred.
Not only does mind/body dualism make sense of immortality, but it also has implications regarding human rationality. According to Physicalism and Epiphenomenalism, people's thoughts, judgments, and actions are determined by physical forces. The problem with determinism is that it is self-refuting: "If my mental processes are totally determined, I am totally determined to either accept or reject determinism. But if my sole reason for believing or not believing X is that I am causally determined to believe it [then] I have no ground for holding that my judgment is true or false" (Owen 118). If all judgments are the result of random chemical motion, then no belief can be held for any reasons whatsoever. Thus, physicalism and epiphenomenalism, if true, are self-refuting because they imply determinism, a view that leaves no room for rational beliefs. Another way to see the force of this argument is to analyze deductive thought. Consider the following syllogism:
Mind/Body Dualism make sense of rationality, but it also has implications for morality. The dualistic perspective is consistent with the reality of moral choices because it allows for the free choice of virtuous actions. However, if human beings are determined machines, then no one would have control over his/her actions, particularly moral actions. It would be absurd for one to say, "‘I ought to jump to the top of a fifty-floor building to save a baby’ since it is not possible for [one] to do that" (Moreland 90). It seems that, for moral decisions to exist, one must have the freedom of choice allowed in mind/body dualism.
Several positive and negative implications follow from substance dualism as an explanatory hypothesis about reality. First, the problem of causal interaction between mind and body is a possible enigma for the substance dualist. Second, the problems of solipsism and personal individuality are indication that dualistic theory needs revision. However, substance dualism has positive implications on issues like personal identity through change and the plausibility life after death; the existence of substantial minds make further sense of human rationality and morally virtuous acts. Substance Dualism is certainly not a dead theory.
Works Cited
Broad, C.D. The Mind and Its Place in Nature. London: Routledge & Kegan Paul, 1925.
Habermas, Gary R. , and Moreland, J.P. Immortality: The Other Side Of Death. Nashville: Thomas Nelson Publishers, 1992.
Moreland, J.P. Scaling the Secular City. Grand Rapids: Baker Book House, 1987.
Owen, H.P. Christian Theism. Edinburgh: T & T Clark, 1984.
Plato, Phaedo. 60c.