You're absolutely right. The folk-dualistic conception of ghosts or spirits or souls is essentially different from Descartes's substance dualism. Folk dualism is actually a materialistic dualism, according to which there are two different kinds of material objects/substances: ones made of some "coarse" or "thick" stuff, i.e. ordinary, readily perceptible solid bodies, and ones made of some "fine" or "thin" stuff, i.e. "subtle", "airy", or "ethereal" bodies.Count Lucanor wrote: ↑January 25th, 2019, 10:10 amPeople who believe in ghosts don't invest much time in thinking about their ontology. These entities are supposedly seen and heard, perceived as moving things and generating noises. A basic analysis of these perceptions indicates that they're only possible under material conditions of being and respond to physical laws. To "see" a ghost implies that light hits its body and bounces as reflection that hits our eyes. Same for hearing them. And for moving things the transmission of a physical force is required. Despite this behavior as physical objects, it is claimed that they can go through the walls. Note that these claims are almost of the same nature as those found in NDE reports, especially in so called OBE (out of body experiences).
See this older post of mine: viewtopic.php?p=284977#p284977
"The idea of an immaterial substance, as it is defined by metaphysicians, is intirely a modern thing, and is still unknown to the vulgar. The original, and still prevailing idea concerning a soul or a spirit, is that of a kind of attenuated aerial substance, of a more subtle nature than gross bodies, which have weight, and make a sensible resistance when they are pushed against, or struck at."
(Priestley, Joseph. Disquisitions Relating to Matter and Spirit. 2nd ed. London: J. Johnson, 1782. p. 72)
"We commonly think that we, as persons, have both a mental and a bodily dimension—or mental aspects and material aspects. Something like this dualism of personhood, I believe, is common lore shared across most cultures and religious traditions, although it is seldom articulated in the form of an explicit set of doctrines as in modern western philosophy and some developed theologies. It is often part of this 'folk dualism' that we are able to survive bodily deaths, as souls or spirits, and retain all or most of the mental aspects of ourselves, such as memory, the capacity for thought and volition, and traits of character and personality, long after our bodies have crumbled to dust.
Spirits and souls as conceived in popular lore seem not be entirely without physical properties, if only vestigially physical ones, and are not what Descartes and other philosophical dualists would call souls or minds—wholly immaterial and nonphysical substances with no physical properties whatever. For example, souls are commonly said to leave the body when a person dies and rise upward toward heaven, indicating that they are thought to have, and be able to change, locations in physical space. And they can be heard and seen, we are told, by people endowed with special powers and in an especially propitious frame of mind. Souls are sometimes pictured as balls of bright light, causing the air to stir as they glide through space and even emitting faint unearthly sounds. But souls and spirits depicted in stories and literature, and in films, are not the immaterial minds of the serious dualist. These latter souls are wholly immaterial and entirely outside physical space."
(Kim, Jaegwon. Physicalism or Something Near Enough. Princeton, NJ: Princeton University Press, 2005. p. 73)