Lofty questions about the mind are fascinating to ask, philosophers have been asking them for three millennia both in India where I am from and here in the West - but it is only in the brain that we can eventually hope to find the answers.

In fact, on one occasion, a rather pedantic experimental psychologist was telling him about a long, complicated experiment he had done, incorporating all the proper controls and using considerable technical virtuosity. When he saw Crick's exasperated expression he said, "but Dr. Crick, we have got it right - we know it's right," Crick's response was, "The point is not whether it's right. The point is: does it even matter whether its right or wrong?"

What do we mean by "knowledge" or "understanding"? And how do billions of neurons achieve them? These are complete mysteries. Admittedly, cognitive neuroscientists are still very vague about the exact meaning of words like "understand," "think," and indeed the word "meaning" itself.

Think about what artists, novelists and poets have in common: the ability to engage in metaphorical thinking, linking seemingly unrelated ideas, such as, 'It is the east, and Juliet is the Sun.'

Lofty questions about the mind are fascinating to ask, philosophers have been asking them for three millennia both in India where I am from and here in the West - but it is only in the brain that we can eventually hope to find the answers.

Indeed, the line between perceiving and hallucinating is not as crisp as we like to think. In a sense, when we look at the world, we are hallucinating all the time. One could almost regard perception as the act of choosing the one hallucination that best fits the incoming data.

The boundary between neurology and psychiatry is becoming increasingly blurred, and its only a matter of time before psychiatry becomes just another branch of neurology.