But the idea of rationality in the cosmos has long existed without monotheism. As far back as the fifth century B.C. the Greek mathematician and philosopher Pythagoras and his followers proclaimed that nature was numbers. Plato envisioned a higher realm of ideal forms, of perfect chairs, circles or galaxies, of which the phenomena of the sensible world were just flawed reflections. Plato set a transcendent tone that has been popular, especially with mathematicians and theoretical physicists, ever since.

FOR more than a quarter-century, the dominant idea guiding economic policy in the United States and much of the globe has been that the market is unfailingly wise. So wise that the proper role for government is to steer clear and not mess with the gusher of wealth that will flow, trickling down to the every level of society, if only the market is left to do its magic.

That notion has carried the day as industries have been unshackled from regulation, and as taxes have been rolled back, along with the oversight powers of government. Faith in markets has held sway as insurance companies have fended off calls for more government-financed health care, and as banks have engineered webs of finance that have turned houses from mere abodes into assets traded like dot-com stocks.

But lately, a striking unease with market forces has entered the conversation. The world confronts problems of staggering complexity and consequence, from a shortage of credit following the mortgage meltdown, to the threat of global warming. Regulation — nasty talk in some quarters, synonymous with pointy-headed bureaucrats choking the market — is suddenly being demanded from unexpected places.