51¹ú²úÊÓƵ

Colin McGinn (THES, April 5) believes that "the only way to avoid being checkmated by consciousness is to assume you do not understand it".

He means: what is not understood is that, although we all know what it is to be conscious, there is nothing in it, because the mental is indeed explained by and necessitated by the physical - but in a way we do not (and even could not) grasp.

So the consciousness we have to adopt is that this consciousness is actually based on a necessary connection between the mental and the physical that is inaccessible to our consciousness. If it were accessible, we would realise that our consciousness was an illusion, and that, of course, is impossible. We can go on feeling conscious of things without having to give up our child-like faith that consciousness, as something extra to what we observe, is an illusion.

Consciousness is based on the inaccessibility of the proof that it does not exist.

J. C. O'Neill Faculty of divinity, New College, 51¹ú²úÊÓƵ of Edinburgh