The ambition to create a simulacrum of a person, as human beings are said to have been created in the image of likeness of God, dates back as far as we can go in the surviving records of human imagination, appearing in different forms in cultures throughout the world. In our time, it has been a favorite theme of science fiction (as in Philip K. Dick's novel, Do Androids Dream of Electric Sheep?, the basis for the movie Blade Runner). Mary Shelley's Frankenstein has been perhaps the most resonant telling of this tale.

Now this age-old ambition has moved from the realm of fantasy and black magic to the realm of science, just as Mary Shelley foresaw. Consider, for example, the December 4, 1998 issue of the journal Science, which includes an article by Giulio Tononi and Gerald M. Edelman entitled "Consciousness and Complexity." Edelman, who received the 1972 Nobel Prize in Physiology or Medicine, is one of several Nobel laureates who have taken up the challenge of Consciousness Studies after making their mark in another field; among the others are Francis Crick, the codiscoverer of the structure of DNA, and the mathematical physicist Roger Penrose.

In fact, over the last fifteen years or so, there has been an extraordinary surge in the study of consciousness. In part this can be attributed to advances in neuroscience. And in part, no doubt, it reflects the lure of a formidable challenge, for consciousness has notoriously resisted scientific explanation. But another factor at work is the desire to disprove, once and for all, the traditional understanding of the human person which, in Western culture, has been deeply influenced by Christianity.

The concluding sentence of Tononi and Edelman's article states that "The evidence available ...