I divide the word into learners and nonlearners. There are people who learn, who are open to what happens around them, who listen, who hear the lessons. When they do something stupid, they don't do it again. And when they do something that works a little bit, they do it even better and harder the next time. The question to ask is not whether you are a success or a failure, but whether you are a learner or a nonlearner.

When it comes to acid rain or oil spills or depleted fisheries or tainted groundwater or fluorocarbon propellants or radiation leaks or sexually transmitted diseases, national frontiers are simple irrelevant. Toxins don't stop for customs inspections and microbes don't carry passports. North America became a water and free-trade zone long before NAFTA loosened up the market in goods.

9/11 was a signal that we were living in a new world - a world of interdependence, a world in which people could attack the United States not from the outside, but from the inside. It was a sign that the United States, the most powerful country in the world, could watch the cathedral of capitalism at the Trade Center and the heart of its defense at the Pentagon be struck internally, not really across borders, so that borders don't matter anymore.

Jefferson thought schools would produce free men: we prove him right by putting dropouts in jail.

The real lesson of 9/11 that I think we have still to learn is that this is a world of interdependence, in which all of the challenges of environment and climate change, of jobs, of disease, of war and terrorism, are cross-border problems that cannot be met one nation at a time.

I divide the world into learners and non-learners.

The question to ask is not whether you are a success or a failure, but whether you are a learner or a nonlearner.