A Simple Argument against Dualism The assumption is that causes and effects occur in space and time. Descartes defines minds as not being located in space and time. According to Descartes' definition of mind, minds can't be causes or effects. Interactions imply causation. So, Descartes' definition is wrong. In order to explain mind-body interaction, minds must be located in space and time. If minds are located in space and time, then Descartes' definition of mind is false, and dualism is false, too.
Descartes' solution is also false. Pineal glands themselves are extended in space and time. Minds that are not extended in space and time cannot be moderated by pineal glands that are extended in space and time.