The philosopher Ludwig Wittgenstein once remarked that if you ask a man how much is two plus two and he tells you five, that is a mistake. But if you ask a man how much is two plus two and he tells you ninety-seven, that is no longer a mistake. The man you are talking to is operating with a wholly different logic from your own.

I attended public school with the same group of kids from K through 12.

Until we fully understand what turned two brothers who allegedly perpetrated the Boston Marathon bombings into murderers, it is hard to make any policy recommendation other than this: We need to redouble our efforts to make America stronger and healthier so it remains a vibrant counterexample to whatever bigoted ideology may have gripped these young men....And the best place to start is with a carbon tax.

Tap into people's dignity and they will do anything for you. Ignore it, and they won't lift a finger.

What I want is natural gas to be a bridge to a cleaner energy future, not a dam against a cleaner energy future, not a dead end. To get this right, to get the most out of it, we not only have to make sure we exploit natural gas in a clean way - it's a challenge - but we also have to make sure that we are instilling and implementing all the incentives to win solar, nuclear energy efficiency that will make them continually competitive with natural gas in the future.

We've gone from thinking the fuels that powered our growth were inexpensive, inexhaustible and benign to understanding they are exhaustible, expensive and toxic. Once you frame the problem that way, people will look at solutions differently.

The Middle East would always be an important trading partner in just a market sense, like America is a big market for us, Asia is a big market, Europe is a big market. You are going to have hundreds of millions of consumers there, from just a standard market point of view, from a very narrow American point of view.