Self-conscious

The reviews are in: I'm Your Man, out just this month, is turning out to be one of the most thought-provoking films of the year. In the film, historian Alma meets Tom, an android who is almost exactly human - except that he can solve complex equations in seconds and speaks every language that has ever existed.

Of course, Tom is actually played by an actor: not a robot pretending to be human at all, but a human pretending to be a robot. But that does not mean the idea of a conscious android is impossible. On the contrary, they may already be among us.

The Aibo is a robotic dog, developed by Sony, that is designed to mimic a real dog in every way. It is covered with sensors, so it can respond when you stroke it or scratch it by nuzzling your palm, and it is programmed to understand 100 words.

The dog is based on neural networksA kind of AI that is capable of so-called "deep learning". It is based on modelling the human brain: like a brain, a neural network can have millions of interconnected nodes., a cutting-edge form of AI that copies the human brain. That means it does not just obey set programmes, it can invent new behaviours: it can learn.

It is the latest in a series of breakthroughs in robots that behave like living things - a revolution that began in 2016 with SophiaA robot that mimics human behaviours. She is a citizen of Saudi Arabia, making her the first robot to receive national citizenship., a robot that imitates human speech and emotions.

But that has some asking: if a robot dog behaves exactly like a dog - or a robot human behaves exactly like a human - is it consciousConsciousness is the name given to our own internal experience of the world and of ourselves.?

This is not a purely theoretical question. In the near future, we might have robots so sophisticated we cannot tell at first glance whether or not they are human. Then we will have to decide how to integrate them into society. Can we justify forcing them to work for us? Should they have human rightsThe basic rights and freedoms that belong to every person in the world, from birth until death. They apply regardless of where you are from, what you believe or how you choose to live your life. Some have called for animals and even natural phenomena like rivers to have some form of human rights.? Should robots be able to get married, own passports, vote?

Part of the problem is that no-one can quite agree on what consciousness is. In philosophy, this is known as the "hard problem of consciousness": the problem of explaining why different people have totally unique first-person experiences that no-one else can access.

Philosopher David ChalmersAn Australian philosopher and cognitive scientist. He is the author of Reality+: Virtual Worlds and the Problems of Philosophy.  has popularised the idea of a "philosophical zombie", a being that looks and acts entirely like a human being, but lacks any consciousness of his own. If you insulted the zombie, it would act angrily in response, but it would not feel any anger internally.

So for him, robots cannot possibly be conscious, because consciousness is more than just the sum of different chemical reactions: it is something mysterious that only human beings have. In fact, with this theory it is impossible to prove conclusively even that other humans are conscious.

Other philosophers think that consciousness does not really exist at all. Daniel DennettAn American analytic philosopher who also came to fame as one of the new atheist thinkers who attacked organised religion in the early 2000s. argues that it is merely an illusion created by various functions of the brain happening at the same time, a position known as "physicalismA philosophical thesis that everything can be explained in terms of the physical, and that nothing exists that does not physically exist.". For them, a robot is self-evidently conscious, because there is no difference between the feelings and reactions that nature has programmed into us, and the responses that humans have programmed into a robot.

Can robots be conscious?

Absolutely, say some. Human beings are simply machines whose programming has been coded in them by evolution. Everything that makes up consciousness - feeling, thought, creativity - can be understood and recreated in a human-built machine. If that machine is not conscious, then neither are we.

Not so fast, say others. There is surely something about consciousness that is irreducible to chemicals and electrical signals. It is a creative, imaginative force that gives rise to new possibilities and can change the laws that govern reality, not just obey them. No robot could ever have this gift.