Will the real George Soros please stand up? The world's most successful investor-and unsuccessful market philosopher-isn't unfamiliar with this plea. To many, he's the original enigma wrapped in a paradox.

If you'd have given him $1,000 in 1969, when he started his Quantum Fund, he'd have turned it into $4 million by the turn of the millennium. As a currency trader, he is notorious for making billions on a daring multibillion dollar bet against the Bank of England's control of the sterling in 1992-and still faces the fist-shaking of Asian leaders who blame him for the currency crisis of 1997. He is simply the world's most feared market mover...

...And so when Soros mentions a 'dollar weakness', as he did in mid-2003, and rails against the White House and "the false ideology that US might gives it the right to impose its will on the world", global investors sit up and listen. Soros, a Budapest-born survivor of two totalitarian regimes, is also famous for deploying his wealth for the cause of 'The Open Society'-the terminology of his guru Karl Popper who argued that since the human being is fallible and society imperfect, we should hold ourselves open to reform. Always.

Amongst Soros' critics are those who dismiss his rants against 'market fundamentalism' as a fig-leaf for a sinister capitalist plot to rule the world-since he makes so much money on the very market he rubbishes. To anyone who has read Soros' famous 1997 Atlantic Monthly article, 'The Capitalist Threat', this would be an unfair caricature of his self-confounding genius. The man quotes Hegel on civilisations failing on account of a "morbid intensification of their own first principles", and asks America to stop obsessing over capitalism as some sort of Ultimate Truth (the attempt to manipulate that, to his mind, is what totalitarianism is, anyway). His own Quantum experience, he says, tells him that markets cannot attain equilibrium-a basic assumption of market theory-since his own decisions tend to alter the circumstances that lead him to those decisions. 'Reflexivity', he calls it.