He said, and I'm paraphrasing, that the most profound thing that's happened with all this internet and media stuff is this: ten or 15 years ago, if you'd wanted to say something in public, to the world at large, you couldn't. You just couldn't do it.
You always had to get access to someone else's media machine. You had to persuade your way or buy your way into the public discourse. You could write a letter to a newspaper, publish a pamphlet, make a sandwich board, do all manner of things, but expressing a personal voice in public was an expensive and difficult thing. You had to do it on someone else's terms. Now, of course, it's trivially easy.
That's a big change. Mr Shirky's thought really struck me hard because it's easy to miss the big differences when you're living and working through the little ones. To start with, the disappearing scarcity of voice explains many of the dilemmas the media and communication worlds are dealing with at the moment. Not so much the everyday, practical ones - How do classified ads compete with online? How do broadcasters distribute their video? How should brands use search engines? - but the slightly more philosophical ones.
When everyone has a voice, what are editorial columns for? How might they change? How should news change? How about opinion polling? When much of the advantage brands had was their ability to buy themselves a voice, what happens now? Should media channels move from being filters to being curators? They should probably continue to rely on their ability to harness and promote unique voices, but where do they find them now? How do they reward them?
These are the big issues of our moment, not whether we should be using twitpic of twitxr. The other implication of Mr Shirky's thought is a generational one. Growing up with the assumption that you'll always be able to publish whatever you want to say, to whoever you want to say it, is going to make people different.
I don't normally hold with all those Gen This, Gen That generalisations, but in this instance it might be true. We're going to need to tweak all sorts of things to get the most from a generation that's used to these expressive possibilities. We'll need to examine how we relate to them as employees, as customers, as colleagues, as voters and as leaders. And, individually, we should maybe start to explore what it's like to be them: we should all go out and start practising expressing our own voice.