Once the ship hits the iceberg, Geithner becomes more central to the action. Home prices fall, the risk-takers are exposed as delusional and, in the ensuing panic, there’s a run on the entire financial system. His job, as he sees it, is to do what he can to plug the hole, and to cram as many people as possible into lifeboats, without worrying too much about appearances. But he is immediately faced with an appearance problem: Before he can save any women and children, he has to rescue the drunks in first class who owned all the lifeboats. “To solve a major financial crisis,” he writes, “you have to do things you would never do in normal times or even in a modest crisis. . . . What feels just and fair is often the opposite of what’s required for a just and fair outcome. It’s why policy makers generally tend to make crises worse, and why the politics of crisis management are always untenable.”

Interestingly, Geithner has little sympathy for those who wanted to see Wall Street bankers held accountable for whatever it was they had done. “Old Testament vengeance” is his pet phrase for such moralistic sentiments, and he argues persuasively that if he had indulged them, the crisis would only have caused more economic pain and suffering for ordinary people. He thinks it was a mistake, for example, to allow Lehman Brothers to fail in September 2008, and writes that he would have prevented it if he could have. (He claims the Treasury and Federal Reserve lacked the authority to save it.) He says President Obama very quickly grasped the merits of ignoring the desire for vengeance, and didn’t ask him to pursue some other, more punitive strategy. As if to ensure that no one leaves confused about his point of view on all this, Geithner argues at the end of his book that the only serious weakness of the Dodd-Frank financial reform measures is that they don’t give the federal government enough power to bail out banks in future crises.

Geithner sees the government’s response to the financial crisis mainly as a great success — though he of course understands that a lot of people don’t agree with him. (“We did save the economy, but we lost the country doing it.”) He clearly thinks people ignore the facts and judge with feeling rather than reason. He himself is careful with the facts. For example, he points out several times that most people seem to believe that the Treasury’s injection of capital into the financial sector cost the taxpayer a fortune when in reality the investments yielded a projected profit of $166 billion. (But he doesn’t mention that the jury is still out on the effects of the less overt but more expensive subsidies flowing from the Federal Reserve.) He finds it silly that many people believe Dodd-Frank changed nothing important. (Yet he never explains why the roughly 5 percent capital ratio it demands of the big banks is anything like a magic number for bank safety — and he does not mention the powerful case recently made by the economists Anat Admati and Martin Hellwig that the right number is at least 20 percent.)

Image Timothy F. Geithner, the former Treasury secretary, in 2012. "We did save the economy," he writes in his new memoir, "but we lost the country doing it." Credit... Luke Sharrett for The New York Times

Geithner seems genuinely to believe that the details of the behavior inside the financial industry are largely irrelevant — that investors who bought subprime mortgage bonds simply suffered from the same misconceptions as everyone else. But he doesn’t begin to explain why, if investors were so numb to risk, Wall Street went to such lengths to disguise that risk. Why did our financiers stuff so many bad loans into incomprehensibly complex securities that even sophisticated investors were unlikely to understand, and then pressure deeply conflicted ratings agencies to declare them risk-free? Subprime mortgage bonds, credit default swaps, collateralized debt obligation synthesized from those credit default swaps, the gaming of the rating agencies, along with the screwed-up behavior of financial elites that seem to me to lie at the heart of the financial crisis, Geithner deems scarcely worth mentioning. His job as financial crisis manager was in part the psychological manipulation of financial markets. It’s odd how little interest he appears to have in the people who work in them.

Finally, he seems to believe that the American financial system is now more or less fully reformed. Those who think the root cause of the crisis was the bad incentives of financiers are unlikely to be persuaded. They made vast fortunes from their colossal failure. There’s no reason they couldn’t or wouldn’t try to fail so well all over again.

But that’s the wrong note to end on. There’s hardly a moment in Geithner’s story when the reader feels he is being anything but straightforward — a near-superhuman feat for someone who spent so much time in public life defending himself from careless and dishonest personal attacks. The decisions he made are easier to criticize than they are to improve upon. I doubt many readers will put his book down and think the man did anything but his best. On his feet he might have stammered and wavered. That in itself was always a sign he was unusually brave.