Under The Microscope

THE MECHANICAL MIND, by Tim Crane;Penguin,1995; 221 pages; $24.95
THE CREATIVE LOOP, by Erich Harth; Penguin, 1995; 196 pages; $21.95

Science and philosophy, working together as cognitive science, are making real progress in understanding the mind. Cognitive science has gone well beyond the simple faith in materialism: of course the mind is the brain at work. The challenge is to explain how the brain implements mental activities.

The model that Tim Crane calls "the mechanical mind" is the orthodox basis of cognitive science. The mechanical mind is computational. Cognition -- perception, thought, reasoning, decision-making -- consists in the algorithmic processing of information that is represented in the mind. The model has many virtues. It uses well-understood computational ideas to indicate how cognition could be realized in the brain's neural networks. It licenses the idea that the brain literally is a computer. The model is not without its informed critics, especially the proponents of connectionism. But the orthodox model is still the best entry to the contemporary science of the mind.

Crane's book presents the computational model with great skill and clarity. It is a splendidly accessible philosophical introduction to the field. Crane is most concerned to explain the fundamental concepts of the model and to examine some philosophical issues that it raises. Scientists often don't bother with these issues. But that doesn't make them go away, for they are genuine problems that the theory must solve. So the book is abstract and, yes, "philosophical", but not in old, discredited ways: it is not proudly ignorant of science and it succeeds very well in demonstrating that philosophical ideas and concerns introduce some much-needed conceptual discipline into an area that attracts more than its fair share of ill-disciplined speculators.

Erich Harth could learn much from Crane's book. Here is yet another (retired) professor of physics who thinks that you don't need any special knowledge or conceptual discipline to study the mind. You just need to let your imagination loose on a few facts. Harth describes his few chosen facts and then lets his imagination rip: that is, he just makes it up. Harth is struck by the presence of descending neural pathways in the brain. These "loops" remind him of creative processes of thought, of the mysteries of intelligence and consciousness. This is ad hoc speculation, and is neither responsible philosophy nor responsible science. The book has nothing to recommend it.

Derek Browne is in the University of Canterbury's Philosophy Department.