"It's really necessary for the United States to continue to give strong leadership to the Middle East peace process, supported by European countries at the same time."

"Spending only what the country can afford, rewarding savings, encouraging independence, supporting marriage: people know that these things are common sense."

"I believe we should reframe our response to climate change as an imperative for growth rather than merely being a way of being green or meeting environmental commitments."

"The war in Iraq, clearly has not turned out in the way that was hoped."

"As in geology, so in social institutions, we may discover the causes of all past changes in the present invariable order of society."

"You are always free to change your mind and choose a different future, or a different past."

"Natural history is not about producing fables."

"You don't have to hold onto the pain to hold onto the memory."