Via the New Inquiry, from the Oberlin College Commencement Address in 1965:
I’m sure that you have read that arresting little story from the pen of Washington Irving entitled Rip Van Winkle. The thing that we usually remember is that Rip Van Winkle slept 20 years. But there is another point in that story that is almost always completely overlooked: he slept through a revolution. When Rip [awoke and] looked up at the picture of George Washington, he was completely lost; he knew not who he was.
There are all too many people who, in some great period of social change, fail to achieve the new mental outlooks that the new situation demands. There is nothing more tragic than to sleep through a revolution. There can be no gainsaying of the fact that a great revolution is taking place in our world today. It is a social revolution, sweeping away the old order of colonialism.