I ask Chomsky how he feels academic freedom and the pursuit of truth are faring in universities. Students, he replies, are not given enough encouragement to challenge the basic assumptions of their professors and the pre-established framework of their subject. He accepts that the situation in Italy is particularly depressing but points out that, when seen from a US perspective, it is true of European universities generally, Britain included. But he stresses that Britain is closer to the US than the continent in this respect.

'Continental Europe still retains a rather authoritarian structure in the university system, with deference/authority relations built into cultural patterns. I noticed it very strikingly when I was teaching at Oxford. In the Oxford college where I was living there was an incident over a man who was serving a young gentleman, and the way he expected to be treated was just unimaginable.

'In the US, class differentiations are not particularly marked, so that the guy who is fixing your car and you are on the same terms.'

He recounts a story about an MIT colleague who, when asked by his students what they were going to cover in their courses, replied that it didn't matter what they covered, but rather what they discovered.

'That's the way education should work,' he says. 'At the graduate level in the sciences that's the way it does work. It's interaction among students and faculty with not much tyranny -- there can't be, because most of the good ideas are coming from the students.'

Mainstream academia, Chomsky complains, tends to be too resistant to change. 'I think you see this very clearly in the way that modern linguistics developed. It did not develop in the major academic centres because they were too conservative. They don't want to be rattled -- they want their peaceful existence to be unchallenged. And that's why in France, where European linguistics took off, it was at Vincennes and not the Sorbonne.

'It was in this little place outside Paris where they were sending all the radical students to get rid of them, and since nobody was paying attention to what happened there, it was possible to have innovative creative work which to this day has not penetrated the French university system. And the same pattern has replicated throughout the world.'

But it is subordination to external power in both US and European universities which he sees as posing perhaps the most serious threat. 'Universities are always in a tension. At best, they are trying to maintain intellectual integrity. Yet they cannot escape the reality that they are parasitic on external power mainly in the form of government and private corporations. These outside pressures are obviously going to undermine intellectual integrity and so it's a constant battle.'

Over-generous funding for over-ambitious projects turns out to be a characteristic speciality of US academia. Following Europe's self-destruction in the second world war, Chomsky explains, the US found itself with unprecedented power and prestige. This led to the confidence, first expressed in the 1950s and still expressed today, that with the US having conquered the world, its scientists could now conquer the last frontier -- the human mind.

'We've just finished a 'decade of the brain' programme backed by major foundations. The closing conference at the United Academy of Arts and Sciences produced the very confident statement that the body/mind problem will soon be overcome and that the mind will finally be understood.

'Well, firstly, there is no such problem, because there has been no coherent concept of body since Isaac Newton, so there's nothing to overcome. And secondly, the confidence is completely misplaced since we can't even explain how the human visual system can recognise a straight line. The truth is that there's still a huge gap between current understanding and the mental aspects of the world we're trying to account for.'

Despite having revolutionised the way we think about language and the mind and notwithstanding the considerable insights produced by almost half a century of sustained research, Chomsky still finds his work criticised outright as 'mentalistic' and therefore unscientific on the grounds that it cannot be reduced to physics. Chemistry, he argues, was not reducible to physics, but that didn't make it unscientific. Rather, it was physics which had to be reconstituted so as to be able to incorporate a virtually unchanged chemistry.

Many modern thinkers, he says, simply haven't understood the full significance of Newton's discovery of gravity. 'The possibility of affecting objects without touching them just exploded physicalism and materialism. It has been common in recent years to ridicule Descartes's 'ghost in the machine' in postulating mind as distinct from body. Well, Newton came along and he did not exorcise the ghost in the machine: he exorcised the machine and left the ghost intact. So now the ghost is left and the machine isn't there. And the mind has mystical properties.

'My feeling is that a study of the actual history of the modern sciences would be a very salutary component of any university curriculum.'

Chomsky acknowledges with a broad grin that these views have earned his approach the trade name of 'MIT mentalism' among colleagues. But why does the conception of the world as consisting in bodies and minds have such a strong hold on people and why are so many academics deceived into believing illusions about the physical that were understood as such 200 years ago?

'So far we've been talking about fact, but now it's speculation. My speculation is that somehow our intuitive mentality is fundamentally dualist. Suppose you're looking at the sun setting over the ocean. You can know all the relativity theory in the world, but you still see the sun setting into the water. And if the moon is near the horizon, you can't help seeing it larger than if it's up in the sky.'

So where does all of this leave truth, the cornerstone of all academic research? Is there a final answer to the question: what is truth? 'There is an answer,' says Chomsky, 'but whether we can find it or not is another matter. The human condition is such that we can make our best guess as to what is true. We're organic creatures and we have our limitations. We must see the world from a particular point of view because that's the way we're built.

'But we're also reflective creatures, so we can reflect on our own inadequacies and try to overcome them. That's what happened in the Newtonian revolution. They had to reflect on the inability of common sense, of ordinary intelligence to comprehend the nature of the world and look at it from a different point of view. It's the same with all our existence. We can use our resources as creatively and critically as we can to try to overcome our special perspectives that come from our nature. But whether we'll get the truth or not is another question.'

Meanwhile, Chomsky's new minimalist programme in linguistics is asking just how well designed the human language capacity is to carry out its essential functions. With complex grammar rules now eliminated in favour of basic principles, he feels that more has been learnt about language in the last 20 years than in the preceeding 2,000 years.

The trouble is, he says, that what we know intuitively seems to lie far beyond what we can understand intellectually.