I have known few greater honors than the opportunity to address the Mother of Parliaments at Westminster Hall. I am told that the last three speakers… - Barack Obama

But we do not have to think that human nature is perfect for us to still believe that the human condition can be perfected. We do not have to live in an idealized world to still reach for those ideals that will make it a better place. The non-violence practiced by men like Gandhi and King may not have been practical or possible in every circumstance, but the love that they preached - their faith in human progress - must always be the North Star that guides us on our journey.

For if we lose that faith - if we dismiss it as silly or naïve; if we divorce it from the decisions that we make on issues of war and peace - then we lose what is best about humanity. We lose our sense of possibility. We lose our moral compass.

But that’s part of what makes America wonderful, is we always had this nagging dissatisfaction that spurs us on. That’s how we ended up going west, that’s how we — “I’m tired of all these people back east; if I go west, there’s going to be my own land and I’m not going to have to put up with this nonsense, and I’m going to start my own thing, and I’ve got my homestead.” ...It is true, though, that that restlessness and that dissatisfaction which has helped us go to the moon and create the Internet and build the Transcontinental Railroad and build our land-grant colleges, that those things, born of dissatisfaction, we can very rapidly then take for granted and not tend to and not defend, and not understand how precious these things are.

The American people will say a prayer for Boston tonight. And Michelle and I send our deepest thoughts and prayers to the families of the victims in the wake of this senseless loss...We still do not know who did this or why. And people shouldn’t jump to conclusions before we have all the facts. But make no mistake - we will get to the bottom of this. And we will find out who did this; we'll find out why they did this. Any responsible individuals, any responsible groups will feel the full weight of justice.