The Mind's I

Part I, "A Sense of Self", begins with two works of fiction that challenge the notions of self and identity (including the Argentine writer Jorge Luis Borges's "Borges and I"), provoking the reader to think more closely about just what is meant by "self". It closes with an essay by Harold J. Morowitz on the reductionist view of the mind.

Part II, entitled "Soul Searching", takes on the idea of soul—that spark which separates thinking beings from unthinking machines. Included here is Alan Turing's famous article from 1950, in which he proposes an operational test—popularly known as the "Turing test"—for machine intelligence, judged successful if a machine can use human language well enough to pass as human. No machine had yet come remotely close to passing the Turing test at the time of the book's publication. (It is argued that merely behaving as if you have human-like intelligence in no way shows that you have human-like intelligence: see Turing test for history and criticisms.) A dialogue of Hofstadter's own picks up the idea of the Turing test and spins a thought-provoking scenario from it.

Two chapters excerpted from a novel by Terrel Miedaner end the section. Hofstadter interprets them in accordance with his own atheistic beliefs, without acknowledgment of Miedaner's opposite intent, which used them to support alternative ideas about the nature of mind and soul.

The formation of mind from elements individually incapable of thought is the central theme of Part III, "From Hardware to Software". The evolution of the mind toward its current state is addressed in the first two reprinted works. Following that is a reprint of "Prelude... Ant Fugue" from Hofstadter's Pulitzer-winning book, Gödel, Escher, Bach, in which he builds up the metaphor of the mind as anthill: each individual part with only rudimentary function, coming together to be more than the sum of its parts.

Part IV explores its titular issue, "Mind as Program". What is the self: the mind, or the body? Can they be separated? Can the location of the consciousness be separate from one's physical location. In that case, where are you, really? Dennett's fantastical account of being separated from his brain and David Sanford's response tackle these issues. In this section the mind is considered as software: as patterns of thought and action, as separate from the physical body housing it as a piece of software is from the machine it runs on.

Part V, "Created Selves and Free Will", includes John Searle's notorious "Minds, Brains, and Programs" (originally an article published in The Behavioral and Brain Sciences, 1980), which states: "...mental processes are computational processes over formally defined elements." Searle has objections to the idea that computer programs might ever produce mind, but the idea that mentality involves computation can be traced through the history of Western philosophy where it has long been explored in the context of trying to explain human reason in terms of formal logical systems. A dramatic and famous rejection of the formal systems idea was that of Ludwig Wittgenstein, a philosopher whom Dennett respects. After first embracing the idea of reducing everything to logical atoms (Tractatus Logico-Philosophicus), Wittgenstein later rejected the idea that human language games should be formulated as formal systems (Philosophical Investigations). However, many philosophers and artificial intelligence researchers remain captivated by the formal systems approach. For example, Dennett has tried to help the MIT Cog project develop formal computer programming methods towards the goal of producing human-like intelligence. In his book "Contemporary Philosophy of Mind", Georges Rey provides an example of continuing attempts to express human intelligence in machines through computational processes over formally defined elements. An alternative but minority approach has grown out of the work of people like Gerald Edelman and his student Olaf Sporns through which it is suggested that machine intelligence can most efficiently be achieved by creating autonomous robotic systems that can learn the way human children learn through interacting with their environment.

The book closes with "The Inner Eye", a collection of short pieces on the subjective nature of experience. How can one describe what it is like to be a particular entity, without actually being it yourself? Thomas Nagel, Raymond Smullyan, Douglas Hofstadter, and Robert Nozick tackle the problem of translating the experiences of one being into terms another can understand. But can we ever know what it is like to be another self? For that matter, what can we know about what it is like to be ourselves? Hofstadter and Dennett's commentary suggest that self-knowledge is elusive, to say nothing of the experience of other minds.