Ryle on substance dualism
Ryle realizes that Descartes-substance-Dualism made an error in grammar, calling it a “categorical mistake”
Descartes assumed that if mental terms are used in seemingly sensical discourse, mental entities must exist. Ryle believed Descartes to be “bewitched by language” and defined categorical mistake as getting confused by common grammar into thinking that two different kinds of things are alike in a way they are not (or vice versa) — i.e. missing the correct categorization.
Example of categorical mistake = imagine someone visits a university, sees the classrooms, libraries, and dorms, and then asks, “But where is the university?” The mistake is assuming “the university” is another physical object like the buildings, rather than the organization or system they together make up.
Descartes made a category mistake of putting the mind and body on the same ontological level. In reality, the mind is an abstract thing or emergent property (of a higher level) made up of the physical body (lower level)
Ryle calls Descartes-substance-Dualism as “the ghost in the machine” where the mind is a “ghost who is everywhere but nowhere”. Descartes’ theory says that real knowledge of someone’s mind would require access to their inner, private mental substance and that while we cannot doubt the existence of our own minds, we can doubt the existence of there minds. Ryle critiques this by saying that our capability to understand mental terms, to recognize emotions in someone else, without having access to the “ghost in the machine” (that is to say without privileged private access to that person’s stream of consciousness) shows that the doctrine is false.
Ryle on behaviorism
Ryle argues in favor of Behaviorism, specifically dispositional behaviorism.
Ryle defines depositions as:
To possess a dispositional property is not to be in a, particular state, or to undergo a particular change; it is to be bound or liable to be in a particular state, or to undergo a particular change, when a particular condition is realized. (p. 43)