Even if his pessimism doesn’t seem wholly warranted, a sense of foreboding surely is, which is why his warnings have to be taken seriously. Mr. Phillips writes that the inventors and marketers of the new financial instruments didn’t entirely understand them. An executive of Fidelity International says a panicky feeling has set in on Wall Street because no one knows where the risks really are. The finance minister of France observes that investments may have reached such a level of complexity that no one can assess them. And Charles R. Morris, in his own gloomy book, “The Trillion Dollar Meltdown,” reports that even Citigroup’s chief financial officer “did not know how to value his holdings.