According to Gilbert Ryle, it is not the function of philosophy to furnish information about minds. Teachers, magistrates, historians, and plain people of all sorts already know the kinds of things that can be known about them, and knowing more is merely a matter of extending one’s experience. Philosophers have access to no special facts; however, if they ply their trade properly, they can help “rectify the logical geography of the knowledge which we already possess.”
As Ryle sees it, most people know how to make correct use of concepts that apply to mental situations but cannot state the “logical regulations governing their use.” Consequently, they do not know how to correlate such concepts with one another or with concepts that refer to matters other than mental facts. The philosopher has the task of clearing up confusions and correcting mistakes that have their source in this kind of ineptness.
It is particularly incumbent on philosophers to do this because, in Ryle’s opinion, most of the difficulties that occur in talking about these matters—for example, the mind-body problem, solipsism, and knowledge of “other minds”—have their origin in the errors of philosophers. In particular, modern European thinkers have great difficulty in throwing off the two-substance doctrine so forcibly stated by French philosopher René Descartes, according to which a person has immediate knowledge of his or her own mind by a kind of interior illumination, greatly superior to the kind of knowledge—never more than an inference—that the individual has of material things. According to this view, which Ryle calls “the official doctrine,” minds dwell in bodies but share none of the characteristics of material things. He frequently stigmatizes it as “the dogma of the ghost in the machine.”