In his 1988 Mind Children (Harvard University Press), Hans Moravec sketched the future development of robots, proposed that within about fifty years it would be possible to transfer human minds into computers, and speculated on the replacement of biological intelligence by machine intelligence. To him, robots would be the creations of our minds just as our children are the creations of our bodies, and since it is our minds that make us most distinctively human, our "mind children" would be our children in the more important sense. At the same time, mind transfer would offer us true immortality.

In Robot: Mere Machine to Transcendent Mind, Moravec tells us that "Among many nice reviews of [the earlier book] an angry few brandished words like ’horrific,’ ’nightmare’ and ’immoral,’ and at least one was too irate to publish." I find that curious, for to a mind steeped in science and science fiction since adolescence, Moravec’s ideas are not terribly strange even if they do push the envelope of what even a visionary scientist might say.

Yet Mind Children was very much a part of a discussion of the potentials of artificial intelligence and robotics that began almost as soon as the first digital computers began chewing their bytes. Norbert Wiener invented cybernetics to "study brainlike activity in animals and machines." And in 1950, Alan Turing proposed that if one could not tell the intellectual difference between a computer and a human conversationalist, there was no such difference. The computer would be intelligent in the only way that matters.

Since then a great deal of effort has gone into meeting the demands of the "Turing test." So far success has been only partial, but there has been enough success to justify immense optimism in the minds of some, such as Moravec. On the other hand, others still resist the notion that a machine, a mere thing, could ever possibly really think. After all, it’s too deterministic, quantum uncertainty is obviously essential to true thought, and it couldn’t possibly have a soul, a mind, emotions, a sense of beauty, a... The list of deficits is endless; it also tends to be revised every time clever programmers figure out how to give a computer a new capability.

To some extent, Robot: Mere Machine to Transcendent Mind is a recapitulation and updating of the earlier book, reviewing the development of robots up to the point where they can take control of their own continuing improvement or evolution. Moravec devotes considerable space to what a civilization dominated by autonomous machines must mean for human economies. He does not shrink from the thought that most humans will be content to eat the lotus in idle bliss, supported by a horde of advanced robots programmed to be happy slaves. That won’t last, though. Some folks will tire of idleness and give up their humanity to become "Exes," robots animated by transferred human minds, and hie off into the far reaches of the galaxy. After a while, they’ll have to move fast when they leave Earth, for natural selection guarantees that our robotic servitors will give rise to more independent sorts, even to predators eager to absorb the materials, energy supplies, and even programs of anything -- including Exes -- that can’t resist or elude them. In other words, there will eventually be a vast and diverse robotic "ecosystem" out in space.

In time, mere robots and Exes will be surpassed by superminds, which in turn will give way to what can only be described as an intelligent universe, a universe converted to computational apparatus and sheer mind in which all reality is virtual. Indeed, what he says is that within this vast "cyberspace," the "real" world will exist only as a simulation of itself. This includes plants, animals, and intelligent beings, and the simulation will be so perfect that no one will be able to tell the difference.

Science fiction readers, who have seen many of these ideas before, find them enchanting. Others find them terrifying, which explains some of the reactions Moravec receives, even from such scientific luminaries as Roger Penrose, who has spent a good deal of effort arguing against the idea of machine intelligence.

Moravec is too polite to call Penrose out in person, but he does borrow the form of Turing’s seminal 1950 paper to attempt -- like Turing -- to lay to rest the various objections to the notion of machine intelligence. These objections he phrases roughly like so:

1. Machines have no souls, so cannot think;

2. Thinking machines cannot be possible, because the consequences would be too dreadful;

3. Mechanical reasoning is too limited;

4. Machines can have no inner experience to give meaning to their "thoughts" or actions;

5. Machines will never be kind, moral, joyous, perceptive, original, etc.;

6. Computers do only what we can program them to do;

7. Computers don’t have nerve cells;

8. It is not possible to specify for a machine what to do in every possible circumstance a human can encounter;

9. Computers can’t have ESP (Moravec considers this a genuine nonissue but deals with it because Turing did).

Moravec is not always convincing, but I do not think it is possible to be more so. The immense leaps in the development of robots and artificial intelligence that he discusses cannot be predicted confidently given the present infantile state of the art. However, it is just as unreasonable for the opposition to say those leaps cannot be made. Both sides display an almost religious adherence to their beliefs. Certainly Moravec has faith in his dreams. His opponents have faith in tradition.

I’m inclined to side with Moravec, and I recommend Robot: Mere Machine to Transcendent Mind as a stimulating, provocative treat for your own mind.