(FORTUNE Magazine) – Of course not. But after reading Lost Prophets (Harvard Business School Press, $27.95), you could be forgiven for thinking they're a pretty accident-prone bunch, theoretically speaking. In the introduction to this survey of economic fashion from the end of World War II to the dawn of the Clinton Administration, Alfred L. Malabre Jr., a longtime Wall Street Journal economics writer, promises to ''ferret out the sensible and useful precepts from those that . . . should have been discarded.'' What he mainly sketches, however, is half a century of failed attempts to translate economic theories into workable policy. The roll call begins with the Bretton Woods fixed-exchange-rate currency system, designed in 1946 by John Maynard Keynes and Harry Dexter White and defunct by 1972. It moves on to LBJ's economic advisers Otto Eckstein and Gardner Ackley, whose chimera was the notion that governmental fine-tuning could free the economy from the ups and downs of the business cycle. Malabre is even less forgiving of Milton Friedman and the monetarists, whose views held center stage after the Keynesians slunk off into the swamp of stagflation in the mid-1970s. But he reserves his most biting criticism for the supply-siders who dominated the early Reagan years and whose legacy, he claims, was not economic growth but rising budget deficits. Partly because of these failures, younger economists have forsaken grand macroeconomic schemes for the pragmatic pursuit of microeconomic analysis. Such modesty, Malabre suggests hopefully, may enable practitioners of the dismal science to deliver a lasting benefit to society.