Each path to knowledge involves different rules and these rules are not interchangeable.

It's not a choice between our environment and our economy; it's a choice between prosperity and decline.

We've got to identify new strategies to use cleaner energy, because that is a recipe for reducing the overall amount of pollution that's out there.

Our Founding Fathers, faced with perils we can scarcely imagine, drafted a charter to assure the rule of law and the rights of man, a charter expanded by the blood of generations. Those ideals still light the world, and we will not give them up for expedience's sake.

I'm named Barack Hussein Obama. I'm African-­American.

There are institutional obligations I have to carry out that are important for a president of the United States to carry out, but may not always align with what I think would move the ball down the field on the issues that I care most deeply about.

I have complete confidence in Secret Service. These guys and gals are unbelievably professional. They know what they’re doing and I basically do what they tell me to do. Now, sometimes I’m the first one to admit that it chafes a little bit being inside this bubble. It’s the hardest adjustment of being president, not being able to just take a walk.