Dennett's former teacher Gilbert Ryle, in his book The Concept of Mind (1949), had also ridiculed the conception of the mind as a "private theater" or "second theater" in Cartesian dualism.[1]
Overview
Descartes originally claimed that consciousness requires an immaterial soul, which interacts with the body via the pineal gland of the brain. Dennett says that, when the dualism is removed, what remains of Descartes' original model amounts to imagining a tiny theater in the brain where a homunculus (small person), now physical, performs the task of observing all the sensory data projected on a screen at a particular instant, making the decisions and sending out commands (see Homunculus argument).
Cartesian materialism is the view that there is a crucial finish line or boundary somewhere in the brain, marking a place where the order of arrival equals the order of "presentation" in experience because what happens there is what you are conscious of. ... Many theorists would insist that they have explicitly rejected such an obviously bad idea. But ... the persuasive imagery of the Cartesian Theater keeps coming back to haunt us—laypeople and scientists alike—even after its ghostly dualism has been denounced and exorcized.[2]
Dennett, Daniel C. (1982). "Styles of mental representation". Proceedings of the Aristotelian Society. 83: 213–226. doi:10.1093/aristotelian/83.1.213. JSTOR4545000. Includes an early use of the term "Cartesian theater".