'In physics and in human affairs... whatever is not surrounded by uncertainty cannot be the truth'

I guess I've finally had enough Feynman," an American Nobel laureate in physics wrote to me when asked to review this collection of letters from and to Richard Feynman, edited by his daughter. It is an understandable reaction. The Feynman "industry", though not quite on a par with the flood of publications by and about Einstein, risks becoming a cult and obscuring Feynman's real achievements and personality. Feynman himself wrote copiously and scintillatingly about both science and himself. Many of the letters in this book are already known from Christopher Sykes's book of reminiscences of Feynman, No Ordinary Genius , and James Gleick's biography, Genius . What do the new ones really add to our understanding?

Perhaps not a great deal about his science. Although there are a fair number of letters strictly about physics, oddly there is none written to major scientific collaborators such as Freeman Dyson, Murray Gell-Mann and Julian Schwinger (and only one extremely brief, non-technical letter to Hans Bethe). Probably such letters have been excluded as too demanding for the expected non-scientific reader, but the reason is not announced by the editor. This is an unashamedly personal, unscholarly collection, as Michelle Feynman makes clear in her lively and touching memoir of her father. Some of the letters lack introductions that would have made them properly comprehensible; there are minimal footnotes; and the index is inadequate, with only one page reference to Einstein, for example, neglecting three other significant references.

Nevertheless the letters contain masses of enjoyable gossip, they throw new light on the development of American science since 1945, and they often sparkle with gems of wit and wisdom. Although Feynman was famously detached from the administration of science - to the irritation of many fellow professionals - he was caught up in great events, notably the wartime building of the atomic bomb and the official inquiry into the Challenger space shuttle disaster. His private reactions to such public events are bound to be of interest; occasionally they are profound.

All geniuses presumably have a struggle with modesty. In Feynman's case, he was without doubt a showman. According to a critical Gell-Mann, quoted in Sykes's book, Feynman "surrounded himself with a cloud of myth, and he spent a great deal of time and energy generating anecdotes about himself".

His letters both support and contradict this accusation in a fascinating counterpoint that becomes a kind of theme in the book. A few letters openly accuse him of being a jerk, but even then his replies are not contemptuous and betray no trace of pomposity.

He seems to have been genuinely ambivalent about whether or not he wanted to win the Nobel prize, which he received in 1965 in his late forties. He certainly made persistent efforts to resign from the National Academy of Sciences. In 1961, he wrote privately to its president, whom he admired as a scientist: "The care with which we select 'those worthy of the honour' of joining the Academy feels to me like a form of self-praise. How can we say only the best must be allowed in to join those who are already in, without loudly proclaiming to our inner selves that we who are in must be very good indeed?" And then he added: "Of course I believe I am very good indeed, but that is a private matter and I cannot publicly admit that I do so, to such an extent that I have the nerve to decide that this man, or that, is not worthy of joining my elite club." As for honorary degrees, he turned down every single one that was offered - on the grounds that they debased genuine degrees.

To Sykes, a BBC television producer who made a widely admired programme with Feynman, The Pleasure of Finding Things Out , he was equally honest. "I get the compliments, and all you get is some remark like 'and there was no buffoon commentator asking you dumb questions', or the like. Little did most people (even some in the business) realise how it was actually done.

They all believed the illusion that all I had to do was open my mouth and talk for an hour. Like all true art, the artist disappears and it looks natural and wonderful." This last comment is Feynman at his most perceptive, and to some extent belies his annoying public display of arrogance about the superiority of science over the arts and humanities.

Even his successful marriage adds to the picture of ambivalence about his celebrity. Feynman's first wife, his childhood sweetheart, died of tuberculosis just months before the completion of the atomic bomb, plunging him into depression. After a brief second marriage (glossed over in the book) and some affairs, he married a gorgeous-looking Englishwoman, Gweneth Howarth. This, despite his marked indifference to English culture. To an unknown English fan of his TV programme who wrote "I don't have a lot of time for most Americans", he responded: "Maybe it would help you with your problem about my being an American to know that my wife is an Englishwoman from Yorkshire. She has probably improved me greatly."

His love for her, and for their two children, is beautifully captured in his letters to them. And so is the affection that he inspired in most of his colleagues and legions of students - Gell-Mann's irritation notwithstanding. During an operation for cancer in 1981, his aorta split, and he needed more than 70 pints of blood. Dozens of students and faculty at the California Institute of Technology, Feynman's longtime home, donated blood to save him. Michelle Feynman remembers that "their love and admiration of my father was palpable".

The physicist Timothy Ferris, in his excellent and objective introduction, quotes from a Feynman letter: "In physics the truth is rarely perfectly clear, and that is certainly universally the case in human affairs. Hence, what is not surrounded by uncertainty cannot be the truth." And then Ferris adds: "It was that spirit, the spirit of science, to which the world responded by cheering Feynman on, and he will be remembered as long as science thrives." Having read this selection of his letters, I confess I find myself cheered and cheering too.

Andrew Robinson, literary editor of The Times Higher , is the joint editor of the letters of Rabindranath Tagore and the author of the forthcoming Einstein: A Hundred Years of Relativity .