Big ideas run throughout the Whedonography, but if you had to pick one big one, it's Whedon's basic suspicion of any forces seeking to bring order to a fundamentally chaotic world. That was true of many of the Buffy Big Bads but especially of the Mayor, a vision of political gladhanding and moral decency. It was also true of the Alliance, the organization in Firefly that was basically a combination of a megacorporation and a national superpower — sort of like a conglomeration of America, China, Goldman Sachs, and Big Tobacco. Loki's motivations are rather tangled in The Avengers, but at one point, he gets in a good line that defines the Whedon villain: ''The bright lure of freedom diminishes your life's joy in a mad scramble for power, for identity. You were made to be ruled.''

There's a great scene in an early episode of Buffy where the Slayer asks mentor Giles if life ever gets any easier. ''What do you want me to say?'' he asked. ''Lie to me.'' And he does:

The good guys are always stalwart and true, the bad guys are easily distinguished by their pointy horns or black hats, and we always defeat them and save the day. No one ever dies, and everybody lives happily ever after.

It might sound like Whedon is cynically denying that simplistic worldview — he is — but he's also underlining a key point of his philosophy: The confusing complexity of the real world is better than the tantalizing moral simplicity of Giles' imaginary universe. Human life is a mess, but it's a mess worth fighting for.