Practical actions may not necessarily be produced by highly theoretical reasoning or by complex sequences of intellectual operations.

The motives of observable actions are propensities and dispositions; these explain why behaviors occur, and not some purely mental process.

To refer to abilities or dispositions as if they were purely mental occurrences is to make a basic kind of category mistake.

Ryle criticizes the theory that the mind is a place where mental images are apprehended, perceived, or remembered.

[5] Category mistakes, such as the ones Ryle points out, are made by people who do not know how to properly wield the concepts with which they are working.

[2][7] According to Bryan Magee, the central thesis of Concept of Mind and the essentials of its subsidiary theses were derived from Schopenhauer, whose works Ryle had read as a student, then largely forgotten.

[8] Ryle has been characterized as an "ordinary language" philosopher,[2] for which the book's style of writing has attracted comment.

Stuart Hampshire remarked in a review in Mind that:[9]There is only one property which I can discover to be common to Professor Ryle and Immanuel Kant; in both cases the style is the philosopher - as Kant thought and wrote in dichotomies, Professor Ryle writes in epigrams.

There are many passages in which the argument simply consists of a succession of epigrams, which do indeed effectively explode on impact, shattering conventional trains of thought, but which, like most epigrams, leave behind among the debris in the reader's mind a trail of timid doubts and qualifications.John Searle, who has often said that no great work of philosophy contains many footnotes and that philosophical quality varies inversely with the number of bibliographical references, considers the absence of footnotes in The Concept of Mind as a sign of its quality.

[11] Ryle has been interpreted by David Stannard as maintaining that the psychoanalytic idea of the unconscious is rooted in the Cartesian conception of a body-mind dichotomy and as such is one version of the "Ghost in the Machine" fallacy.

According to Stannard, Ryle views the dogma as a logical error based on a category mistake.

Webster attributes this to the fact that Ryle's case that subjective aspects of experience such as sensation, memory, consciousness and sense of self are not the essence of "mind" has not been universally accepted by contemporary philosophers, neuroscientists, and psychologists.

Webster stresses that Ryle does not deny the reality of what are often called internal sensations and thoughts, but simply rejects the idea that they belong to a realm logically distinct from and independent of the external realm of ordinary human behaviour.

[1] The book's style of writing was commented on more negatively by Herbert Marcuse, who observes that the way in which Ryle follows his presentation of "Descartes' Myth" as the "official doctrine" about the relation between body and mind with a preliminary demonstration of its "absurdity" which evokes "John Doe, Richard Roe, and what they think about the 'Average Taxpayer'" shows a style that moves "between the two poles of pontificating authority and easy-going chumminess," something Marcuse finds to be characteristic of philosophical behaviorism.