The lesson of these experiments is not that people are shortsighted or shallow but that their preferences aren’t consistent over time. We want to watch the Bergman masterpiece, to give ourselves enough time to write the report properly, to set aside money for retirement. But our desires shift as the long run becomes the short run.

Why does this happen? One common answer is ignorance. Socrates believed that akrasia was, strictly speaking, impossible, since we could not want what is bad for us; if we act against our own interests, it must be because we don’t know what’s right. Loewenstein, similarly, is inclined to see the procrastinator as led astray by the “visceral” rewards of the present. As the nineteenth-century Scottish economist John Rae put it, “The prospects of future good, which future years may hold on us, seem at such a moment dull and dubious, and are apt to be slighted, for objects on which the daylight is falling strongly, and showing us in all their freshness just within our grasp.” Loewenstein also suggests that our memory for the intensity of visceral rewards is deficient: when we put off preparing for that meeting by telling ourselves that we’ll do it tomorrow, we fail to take into account that tomorrow the temptation to put off work will be just as strong.

Ignorance might also affect procrastination through what the social scientist Jon Elster calls “the planning fallacy.” Elster thinks that people underestimate the time “it will take them to complete a given task, partly because they fail to take account of how long it has taken them to complete similar projects in the past and partly because they rely on smooth scenarios in which accidents or unforeseen problems never occur.” When I was writing this piece, for instance, I had to take my car into the shop, I had to take two unanticipated trips, a family member fell ill, and so on. Each of these events was, strictly speaking, unexpected, and each took time away from my work. But they were really just the kinds of problems you predictably have to deal with in everyday life. Pretending I wouldn’t have any interruptions to my work was a typical illustration of the planning fallacy.

Still, ignorance can’t be the whole story. In the first place, we often procrastinate not by doing fun tasks but by doing jobs whose only allure is that they aren’t what we should be doing. My apartment, for instance, has rarely looked tidier than it does at the moment. And people do learn from experience: procrastinators know all too well the allures of the salient present, and they want to resist them. They just don’t. A magazine editor I know, for instance, once had a writer tell her at noon on a Wednesday that the time-sensitive piece he was working on would be in her in-box by the time she got back from lunch. She did eventually get the piece—the following Tuesday. So a fuller explanation of procrastination really needs to take account of our attitudes to the tasks being avoided. A useful example can be found in the career of General George McClellan, who led the Army of the Potomac during the early years of the Civil War and was one of the greatest procrastinators of all time. When he took charge of the Union army, McClellan was considered a military genius, but he soon became famous for his chronic hesitancy. In 1862, despite an excellent opportunity to take Richmond from Robert E. Lee’s men, with another Union army attacking in a pincer move, he dillydallied, convinced that he was blocked by hordes of Confederate soldiers, and missed his chance. Later that year, both before and after Antietam, he delayed again, squandering a two-to-one advantage over Lee’s troops. Afterward, Union General-in-Chief Henry Halleck wrote, “There is an immobility here that exceeds all that any man can conceive of. It requires the lever of Archimedes to move this inert mass.”

McClellan’s “immobility” highlights several classic reasons we procrastinate. Although when he took over the Union army he told Lincoln “I can do it all,” he seems to have been unsure that he could do anything. He was perpetually imploring Lincoln for new weapons, and, in the words of one observer, “he felt he never had enough troops, well enough trained or equipped.” Lack of confidence, sometimes alternating with unrealistic dreams of heroic success, often leads to procrastination, and many studies suggest that procrastinators are self-handicappers: rather than risk failure, they prefer to create conditions that make success impossible, a reflex that of course creates a vicious cycle. McClellan was also given to excessive planning, as if only the ideal battle plan were worth acting on. Procrastinators often succumb to this sort of perfectionism.

Viewed this way, procrastination starts to look less like a question of mere ignorance than like a complex mixture of weakness, ambition, and inner conflict. But some of the philosophers in “The Thief of Time” have a more radical explanation for the gap between what we want to do and what we end up doing: the person who makes plans and the person who fails to carry them out are not really the same person: they’re different parts of what the game theorist Thomas Schelling called “the divided self.” Schelling proposes that we think of ourselves not as unified selves but as different beings, jostling, contending, and bargaining for control. Ian McEwan evokes this state in his recent novel “Solar”: “At moments of important decision-making, the mind could be considered as a parliament, a debating chamber. Different factions contended, short- and long-term interests were entrenched in mutual loathing. Not only were motions tabled and opposed, certain proposals were aired in order to mask others. Sessions could be devious as well as stormy.” Similarly, Otto von Bismarck said, “Faust complained about having two souls in his breast, but I harbor a whole crowd of them and they quarrel. It is like being in a republic.” In that sense, the first step to dealing with procrastination isn’t admitting that you have a problem. It’s admitting that your “you”s have a problem.

If identity is a collection of competing selves, what does each of them represent? The easy answer is that one represents your short-term interests (having fun, putting off work, and so on), while another represents your long-term goals. But, if that’s the case, it’s not obvious how you’d ever get anything done: the short-term self, it seems, would always win out. The philosopher Don Ross offers a persuasive solution to the problem. For Ross, the various parts of the self are all present at once, constantly competing and bargaining with one another—one that wants to work, one that wants to watch television, and so on. The key, for Ross, is that although the television-watching self is interested only in watching TV, it’s interested in watching TV not just now but also in the future. This means that it can be bargained with: working now will let you watch more television down the road. Procrastination, in this reading, is the result of a bargaining process gone wrong.

The idea of the divided self, though discomfiting to some, can be liberating in practical terms, because it encourages you to stop thinking about procrastination as something you can beat by just trying harder. Instead, we should rely on what Joseph Heath and Joel Anderson, in their essay in “The Thief of Time,” call “the extended will”—external tools and techniques to help the parts of our selves that want to work. A classic illustration of the extended will at work is Ulysses’ decision to have his men bind him to the mast of his ship. Ulysses knows that when he hears the Sirens he will be too weak to resist steering the ship onto the rocks in pursuit of them, so he has his men bind him, thereby forcing him to adhere to his long-term aims. Similarly, Thomas Schelling once said that he would be willing to pay extra in advance for a hotel room without a television in it. Today, problem gamblers write contracts with casinos banning them from the premises. And people who are trying to lose weight or finish a project will sometimes make bets with their friends so that if they don’t deliver on their promise it’ll cost them money. In 2008, a Ph.D. candidate at Chapel Hill wrote software that enables people to shut off their access to the Internet for up to eight hours; the program, called Freedom, now has an estimated seventy-five thousand users.