Why did so many people fall for his tricks? Mr. Akst lines up all the usual suspects - greed, Reaganism, charisma, human frailty, even the wacky ways of southern California. Yet these account for only part of Mr. Minkow's success. The other part has to do with the fact that business relies on some pragmatic ethical assumptions - for example, that a contract is a real contract and that a promise will be kept. Characters like Mr. Minkow do more than break the law. They create moral anarchy by wreaking havoc with the trust and good will that lie at the heart of business practice. As Mr. Akst correctly observes, ''Barry wasn't just a thief. He had mocked the very idea of business.''