"They helped put an end to the idea that the universe is an idea, that beyond the mundane business of making our way as best we can in a world shot through with contingency, there exists some order, invisible to us, whose logic we transgress at our peril." Academic freedom and cultural pluralism are just two of their legacies, and they are linchpins of democracy in a nonideological age.

A hundred years from now, a great writer will produce a Pulitzer Prize winning book about the most significant debates in the intellectual sphere at the turn of the century. Bill Joy will figure in it, although he will end up looking a lot like Louis Agassiz. Francis Fukuyama will be there, too. He will fare better than Joy, but the lesson will be clear: you can change your mind about an idea, but it is considerably more difficult to reposition yourself in the social network. You can alienate former colleagues easily enough, but good luck trying to build support with your former opponents.

Oh, the irony. How naïve we were in the early days.