Colin McGinn was once introduced to the actress Jennifer Aniston at a party. Although Aniston was impressed to meet a professional philosopher, the encounter ended in embarrassment when she proved never to have heard of Kant, Descartes or Bertrand Russell. McGinn subsequently agonised over the "interpersonal discomfort" caused to the poor multimillionaire movie star.
Aniston is not the only person who has been made uncomfortable by the author of this superb intellectual autobiography. During his career, McGinn has infuriated other, more notable thinkers. One of the grand old men of British philosophy, Michael Dummett, once subjected him to an angry tirade during a seminar, and Daniel Dennett has dismissed his claims as "embarrassing". The claims to which Dennett was referring are at once bold and modest: most philosophical problems, McGinn believes, will never be solved because of our intellectual shortcomings.
McGinn's early underachievement in the classroom may have influenced him in adopting this view. He failed his eleven-plus, was sent to a secondary modern in Blackpool but still made it to Manchester University where his heroes were John Lennon and Bertrand Russell, a difficult pair to imitate at the same time. Opting for the latter, McGinn began smoking Russell's favourite brand of pipe tobacco in the hope that it would make him as clever as the man himself. Finding that it did not, he moved on to Noam Chomsky, who was to become his greatest influence.
McGinn was taken with the dark flip side of Chomsky's discovery of a form of innate knowledge possessed by all human beings - the possibility of innate ignorance. If our acquisition of language during infancy depends on an inbuilt grasp of grammar, as Chomsky has argued, there may be other branches of knowledge where we are not so fortunately endowed. The author's favourite is the question of how the brain generates consciousness. The problem, he argues, cannot be tackled in the normal fashion, which is by taking things apart and putting them back together again. This is the method by which we usually come to see how one kind of object - say, a kidney - depends upon another kind, in this case, cells.
Although consciousness relies on the firing of neurons, our experiences are not literally composed of neural activities but of shapes, lines, sounds and so on. Unlike most organs in the body, in other words, the mind is not a mere aggregation of simpler parts. When it comes to understanding consciousness, there is an explanatory gap we are powerless to bridge. We find the problem difficult because we lack the requisite cognitive equipment for finding a solution. Had evolution given us intellectual faculties of a different kind, the answer might seem obvious and the subject no more profound than plumbing.
In truth, there is no reason why we should expect to be capable of understanding every last thing in nature. But this is no excuse for not trying. At some point in the future, McGinn's pessimism may be appropriate, but we do not know when this day will arrive. If there are things we are constitutionally incapable of knowing, then where to draw the line might be one of them.
McGinn offers one of the best introductions to contemporary Anglo-American philosophy, yet he remains curiously in denial about the many genuine advances of recent decades. When I interviewed McGinn last year at his home in New York, he seemed comfortable with his own scepticism. As another philosopher was proud to boast, at least he knows that he knows nothing.
Nicholas Fearn is the author of Zeno and the Tortoise: how to think like a philosopher (Atlantic Books)