The Emperor's New Mind

The Emperor's New Mind: Concerning Computers, Minds and The Laws of Physics is a 1989 book by mathematical physicist Roger Penrose.

Penrose presents the argument that human consciousness is non-algorithmic, and thus is not capable of being modeled by a conventional Turing machine-type of digital computer. Penrose hypothesizes that quantum mechanics plays an essential role in the understanding of human consciousness. The collapse of the quantum wavefunction is seen as playing an important role in brain function.

The English version of the book is 602 pages long. The majority of the book is spent reviewing, for the scientifically minded layreader, a plethora of interrelated subjects such as Newtonian physics, special and general relativity, the philosophy and limitations of mathematics, quantum physics, cosmology, and the nature of time. Penrose intermittently describes how each of these bears on his developing theme: that consciousness is not "algorithmic". Only the later portions of the book address the thesis directly, and Penrose admits that his ideas on the nature of consciousness are quite speculative.

The book does not discuss the implications of quantum computers for his theory of consciousness, as it somewhat predated developments in the field of quantum computation. Following the publication of this book, Penrose began to collaborate with Stuart Hameroff on a biological analog to quantum computation involving microtubules, which became the foundation for his subsequent book, Shadows of the Mind: A Search for the Missing Science of Consciousness.

The book attacks the claims of artificial intelligence using the physics of computing: Penrose notes that the present home of computing lies more in the tangible world of classical mechanics than in the imponderable realm of quantum mechanics. The modem computer is a deterministic system that for the most part simply executes algorithms. To show this Penrose takes a billiard table, by reconfiguring the boundaries of a billiard table, one might make a computer in which the billiard balls act as message carriers and their interactions act as logical decisions. The Billiard-Ball Computer was first designed some years ago by Edward Fredkin and Tommaso Toffoli of the Massachusetts institute of Technology.

Penrose won the |Aventis prize in 1990 for this book.