Barack Obama has a good Al Gore story. Sometime after the 2000 election, Obama called on a corporate executive in a big office with a terrific view of midtown Manhattan. The businessman had been an ardent Gore supporter, and the former vice president had recently asked him to consider investing in a startup television venture. "It was strange," the executive told Obama. "Here he was, a former vice president, a man who had just a few months earlier been on the verge of being the most powerful man on the planet. During the campaign, I would take his calls any time of day, would rearrange my schedule whenever he wanted to meet. But suddenly, after the election, when he walked in, I couldn't help feeling that the meeting was a chore. I hate to admit it, because I really like the guy. But at some level he wasn't Al Gore, former vice president. He was just one of the hundred guys a day who are coming to me looking for money. It made me realize what a big steep cliff you guys are on." Obama, recounting the anecdote in "The Audacity of Hope," notes: "A big steep cliff, the precipitous fall." And, in Gore's case, the climb back up the cliff, to a Nobel Peace Prize and global eminence. Obama, who is now arguably the most powerful man in the world, understands that power is a fluid thing, and has been since the first caveman threw a rock at another caveman. (Story continued below...)

In the popular imagination, power tends to be viewed in one of two ways, both extreme. The first is totemic and tactical (how to get ahead at the office, to win friends and influence people). The other is epic and amorphous (the fate of markets, of vast global events and forces that seem beyond anyone's control, but especially yours).

Power is both these things, and more. At heart, it is best understood in terms of command and control. It is either the capacity to make others do as you wish (the command function) or to reorder the environment around you (the control function).

To study it intimately and specifically—how people get power, and how they wield it—is not only diverting (though, as Homer and Shakespeare knew, it is surely that). It is also illuminating, for understanding its accumulation and deployment enables us to learn, possibly, how to change the world around us, and the world at large.

Forgive that last bit of Dawn-of-the-Age-of-Obama hyperbole, but there is real hope behind the hype of the season. The discussion of power makes many left-of-center Americans somewhat uncomfortable, for it can be offensive to democratic sensibilities. Many right-of-center Americans, too, find the conversation unsettling, for it inevitably leads to thoughts of a governing elite, which conservatives in recent decades have chosen to vilify for rhetorical purposes. From Plato forward, philosophers have struggled to define power and, in the act of definition, to delineate it from the other impulses that shape what we do.