A book by the philosopher
Gilbert Ryle, published in 1949, attacking the
cartesian dogma of a
mind separate from the body.
The book is one of the central planks of the analytic philosophy approach, and was hugely influential. Before it, the idea that minds were separate from brains and bodies was effectively the "official doctrine" as Ryle termed it. After it, it was difficult for any serious philosopher to maintain that the mind existed as a different kind of thing, as proposed by René Descartes.
Ryle coined the deliberately abusive expression "Ghost in the Machine" to caricature the prevailing doctrine. Another likeness he used was of a horse in the locomotive. He said that the prevailing doctrine held that the ordinary visible, physical behaviour of a human being was not enough to explain our thoughts, feelings, and other such mental activity, and that therefore there must be some private inner realm, a "mind", that sat inside the person and observed what the sensory data brought in. But the mind was supposed to be different from the merely physical receiver of sensation.
The recurring theme of Ryle's attack on this dogma is that it is a category mistake. It confuses entirely different kinds of things. Over and over again he offers examples such as this: when I write a node carefully, I am only doing one thing. I am not (a) writing a node, and (b) being careful. The care I exercise isn't an additional, separate, superadded activity, looking over the primary activity of the node-writing. They are one and the same things. To regard them as two activities is to make the mistake of calling "being careful" a kind of activity I do, on a par with, or in the same category as, the activity of writing.
He demonstrates that a huge range of things we "do" in the mental sense (concentrating, understanding, judging, supposing, expecting, etc. etc.) are not things we do, but rather they are ways we do things such as playing card-games, teaching children, practising for tests, solving crossword-puzzles, and so on. These latter are overt behavioural acts, and the mental component is part of how we do them. It is not a distinct mental "action". So no distinct agent, a "mind", is required to account for them.