He was an infant prodigy. He began learning the violin at the age of 3 and gave his first performance at 7 with the San Francisco Symphony Orchestra. By 13 he was playing in Berlin under Bruno Walter. It is rumoured that after the concert Albert Einstein exclaimed: “Now I know there is a God” - a dodgy remark from the musical and theological points of view.

The young Yehudi Menuhin became the darling of the concert circuit, his blond head poised seriously over his instrument, the notes flowing with easy grace to the enchantment of rapt audiences around the world. He was a musical phenomenon. He went on to do many worthy things with his life: founding the Menuhin school was merely one of them. And he got used to speaking out on many matters - so many, in fact, that people didn't always heed what he said. The BBC archive has yielded up a gem.

I have been researching a programme for Archive Hour on BBC Radio 4. Tucked away in its millions of records, we are tracking down a series of dialogues held in the Sixties and Seventies in the Church of St Mary-le-Bow, in Cheapside, London. On a regular weekday lunchtime, the vicar, the Rev Joseph McCulloch, opened his doors and his pulpits (he had two) to a stream of distinguished speakers who came to discuss issues of the moment.

These were the days before literary festivals, book groups or even many television channels. So the place was always packed. I know because I would stand in for Joseph whenever the guest of the day was one of his fellow clergy: he felt awkward about interviewing them himself. So I was not in conversation with Menuhin when he had this to say about the country's resources: “We are really facing a crisis and the future would be better assured by the renouncing of the use of oil altogether, for a period of time, while we developed other power and other means of locomotion.

“There is plenty of power around - steam, winds, tides, heat from the centre of the earth, from the sun - but we are led by habit, conditioned to go only one way.”

The year was 1970, three years before the oil hike, when the oil trading nations really took a stranglehold of the world's resources. No one listened to what he had to say: why should they? He was a maestro with the violin and his opinions were heard with no more than polite attention and then completely ignored.

I wonder how many other great insights have been made and expressed while the world looks the other way, and what it takes for an idea to really take off and change our whole perspective? Some of the evidence is, wonderfully, on display at the Darwin exhibition at the Natural History Museum in London.

Darwin, of course, had one of history's big ideas. And in advance of the 150th anniversary next year of the publication of his magnum opus, the exhibition tells in meticulous detail how he made and recorded his discoveries - we see a number of his specimen finches on display - analysed them over 20 years, and then brought them to fruition in On the Origin of Species in 1859.

Darwin's was not a lone voice crying in the wilderness at all. The background to his work was dense with loyalty, encouragement and practical help. He came from a family in which ideas were valued; he had the benefit of a modest private income that allowed him to take that fateful five-year journey on The Beagle unpaid; he was already familiar as a student with the evolutionary ideas of Lamarck; he had the continuing interest and help of his Cambridge mentor Professor Henslow; and returning to England he could hide himself away in the country to do some sustained thinking.

The path towards the great breakthrough was well prepared. Even as he was working on the text of On the Origin of Species, Alfred Russel Wallace sent him an essay describing the very same idea. It isn't to demean the grandeur of Darwin's achievement to suggest that the idea was already in the air. He gave years of his life to the most precise and thorough research. And he kept thinking - thinking and reading. It was this sustained concentration that brought forth the work. By comparison Menuhin's concern for the planet was an aside in a life busy with other achievements and successes.

We want the next generation to go on having big ideas, ideas as big as Darwin's. The question is how are we to make that possible? Where can anyone these days find the quiet confidence to pursue without anxiety their early impulses and insights. Even the depths of university departments are awash with worries about funding.

Research scientists are too often dependent on institutions - pharmaceutical companies and such - that prefer the prospect of commercial gain to come with their grant-giving. It is even worse in schools, where children are so systematically dragooned for most of their education. The curriculum allows for choice certainly, but not for those rewarding day-dreaming moments when ideas ferment and new connections are made. Without them originality becomes impossible.

And then there are the distractions: iPods, mobile phones, Facebook. It is almost as though plain thinking is being crowded out by an excess of sensory input. The world is noisier, more insistent, more competitive and more relentless than it used to be.

The still, small but insistent voice of inspiration may well have difficulty making itself heard.

joanbakewell@thetimes.co.uk