In my Intro. course, we read Descartes’ Meditations, in part using it to introduce the complicated and important set of issues known as the mind-body problem.
The most ancient account of the mind-body relation is dualism, the view that the mind and the body are two different types of stuff that are temporarily joined. The broadest contrast competitor account is physicalism, the view that the mind and the body are both ultimately physical, the mind being a set of dependent capacities that emerge from or are reducible to physical capacities.
On the traditional dualist account (especially traditional religious dualist accounts), human beings are a microcosm of a dualist macrocosm: Reality for dualists is divided into a physical natural world and a non-physical supernatural world. We humans have a metaphysical foot in each camp, so to speak — a physical body attached to the natural world and a temporarily-housed spirit that wants (or should want) to be reunited with the supernatural.
Martin Luther is representative, here writing in 1520: “Man has a twofold nature, a spiritual one and a bodily one. According to the spiritual nature, which men refer to as the soul, he is called a spiritual, inner, or new man. According to the bodily nature, which men refer to as flesh, he is called a carnal, outward, or old man, of whom the Apostle writes in 2 Cor. 4 [:16], ‘Though our outer nature is wasting away, our inner nature is being renewed every day.’ Because of this diversity of nature the Scriptures assert contradictory things concerning the same man, since these two men in the same man contradict each other, ‘for the desires of the flesh are against the spirit, and the desires of the Spirit are against the flesh,’ according to Gal. 5 [:17].”
Descartes (1596-1650) is a dualist, defending it against the rising number of physicalists who want to explain human beings without appealing to immaterial souls, spirits, or substances. Thomas Hobbes (1588-1679) is a contemporary-to-Descartes example:
“For seeing life is but a motion of limbs, the beginning whereof is in some principal part within; why may we not say, that all automata (engines that move themselves by springs and wheels as doth a watch) have an artificial life? For what is the heart, but a spring; and the nerves, but so many strings; and the joints, but so many wheels, giving motion to the whole body … ?” (Leviathan, 1651)
The debate is many-dimensional, and for many dualists the primary issue is not so much whether physicalism is an adequate explanation for the human psyche but rather the value implications. If physicalism is true, won’t that mean that when our bodies die, that’s it, and doesn’t that make life depressingly pointless? If physicalism is true, then doesn’t that undermine our human dignity and reduce us to level of the other beasts? And wouldn’t that mean that there’s no soul to check our lower, animalistic desires for sex, food, and drink? If there’s no soul, then doesn’t that mean that there’s no afterlife to look forward to?
Of course, the value implications also cut the other way. If dualism is true, then doesn’t that divorce love from sex, as in dualistic Platonic love? Doesn’t dualism separate the higher moral realm from practical, real-life concerns? Doesn’t dualism pit the mind against the body rather than expecting that they can and should work together harmoniously? Doesn’t dualism encourage people to waste their lives waiting for an afterlife rather than pursuing the good life here in the natural world? And on the issue of human dignity, my favorite response here comes from Raymond Smullyan:
“Recently I was with a group of mathematicians and philosophers. One philosopher asked me whether I believed man was a machine. I replied, ‘Do you really think it makes any difference?’ He most earnestly replied, ‘Of course! To me it is the most important question in philosophy.’ I had the following afterthoughts: I imagine that if my friend had finally come to the conclusion that he were a machine, he would be infinitely crestfallen. I think he would think: ‘My God! How horrible! I am only a machine!’ But if I should find out I were a machine, my attitude would be totally different. I would say: ‘How amazing! I never before realized that machines could be so marvelous!’”
[Autobiographical sideline: Raymond Smullyan was one of my professors in graduate school at Indiana University. Indiana’s philosophy department was then heavily focused on logic, epistemology, and analytic metaphysics, and across the quad the university had a strong and separate History and Philosophy of Science department. Douglas Hofstadter was also at Indiana then, having been lured back from Michigan to head Indiana’s Center for Research on Concepts and Cognition. Intellectually exciting times. Coincidentally and unknown to me at the time, Jimmy Wales was then at Indiana pursuing a Ph.D. in business, and Elinor Ostrom, 2009 Nobel Prize winner in economics, was also there in the political science department.]
Related: Descartes’s Meditations, in the Philosophers, Explained series.
Nice summary. Its interesting the way that you show that dualism can be a reaction to the idea that we are ‘machines’. My own view is that dualism and materialism are two sides of the same coin – both dualists and materialists argue on the basis of simple materialist cosmology to explain physical events. See Materialists should read this first