In his book The End of the World: The Science and Ethics of Human Extinction John Leslie, professor of philosophy at Guelph University in Canada, predicts ways in which intelligent machines might cause the extinction of mankind. He says that super-clever machines might argue to themselves that they are superior to humans.
They might eventually be put in charge of managing resources and decide that the most efficient course of action is for humans to be removed. He also believes it would be possible for machines to override in-built safeguards.
"If you have a very intelligent system it could unprogram itself," he says. "We have to be careful about getting into a situation where they take over against our will or with our blessing."
Even if there exists a distant danger, some experts say it is much too soon to start panicking. Rodney Brooks, director of the Artificial Intelligence Laboratory at Massachusetts Institute of Technology (MIT) says we can't hope to accurately imagine how things may pan out just yet.
"I think that this is a little like worrying about noise abatement issues at airports back during mankind's first attempts at a hot air balloon," he says.
Ray Kurzweil, author of The Age of Spiritual Machines: When Computers Exceed Human Intelligence, also believes it is possible to overreact to a vision of robotic Armageddon and says the potential benefits make it impossible to turn our backs on the benefits of artificial intelligence.
"People often go through three stages in examining the impact of future technology," says Kurzweil in an article responding to Bill Joy's polemic, titled Promise and Peril: Deeply Intertwined Poles of Twenty First Century Technology.
"Awe and wonderment at its potential to overcome age old problems, then a sense of dread at a new set of grave dangers that accompany these new technologies. Followed, finally and hopefully, by the realisation that the only viable and responsible path is to set a careful course that can realise the promise while managing the peril."
Surprisingly, there are even experts who would welcome the possibility of machines taking over from humans. Professor Hans Moravec is well known for his belief that machines will inherit the earth - he even welcomes the prospect.
Moravec said in a recent interview that the majority of significant human evolution has taken place on a cultural level and therefore replacing biological humans with mechanical machines capable of far greater learning and cultural development is the next logical step in evolution.
So what may be the best course of action? Marvin Minsky is an artificial intelligence pioneer who founded the AI Lab at MIT and is on the board of advisors at the Foresight Institute, a body created to investigate the dangers of emerging technologies.
Minsky agrees that extinction at the mechanical hands of a robot race may be just around the corner, but says that developments in the field of artificial intelligence call for considered debate. He says he is encouraging artificial intelligence experts to participate in the work of the Institute.
"Our possible futures include glorious prospects and dreadful disasters," says Minsky in an email. "Some of these are imminent, and others, of course, lie much further off."
Minsky notes that there are more immediate threats to think about and combat, such as global warming, ocean pollution, war and world overpopulation. However, he says, the possibilities of artificial intelligence should not be completely ignored.
"In a nutshell, I argue that humans today do not appear to be competent to solve many problems that we're starting to face. So, one solution is to make ourselves smarter - perhaps by changing into machines. And of course there are dangers in doing this, just as there are in most other fields - but these must be weighed against the dangers of not doing anything at all."
Minsky adds a warning for those who question whether machines may ever become intelligent enough to better us.
"As for those who have the hubris to say that we'll 'never' understand intelligence well enough to create or improve it, well, most everyone said the same things about 'life' - until only a half dozen decades ago."
It's *Isaac* Asimov