Thunder

“When you run with the Doctor, it feels like it'll never end. But however hard you try you can't run forever. Everybody knows that everybody dies and nobody knows it like the Doctor. But I do think that all the skies of all the worlds might just turn dark if he ever for one moment, accepts it. Everybody knows that everybody dies. But not every day. Not today. Some days are special. Some days are so, so blessed. Some days, nobody dies at all. (In the library, the Doctor walks back to the TARDIS. He stops, looking at the doors. Then he raises his hand, and stands there poised like that for a long moment. Finally he snaps his fingers. The doors open. He smiles slowly and walks in, joining Donna. Then he snaps his fingers again, and the doors close. River's voice continues over this.) Now and then, every once in a very long while, every day in a million days, when the wind stands fair, and the Doctor comes to call... everybody lives.”
― Steven Moffat

“I travelled across the world. From the ruins of New York, to the fusion mills of China, right across the radiation pits of Europe. And everywhere I went I saw people just like you, living as slaves! But if Martha Jones became a legend then that's wrong, because my name isn't important. There's someone else. The man who sent me out there, the man who told me to walk the Earth. And his name is The Doctor. He has saved your lives so many times and you never even knew he was there. He never stops. He never stays. He never asks to be thanked. But I've seen him, I know him... I love him... And I know what he can do. - Martha Jones”
― Russell T. Davies

“He's like fire and ice and rage. He's like the night, and the storm in the heart of the sun. He's ancient and forever. He burns at the center of time and he can see the turn of the universe. And... he's wonderful. - Tim Latimer”
― Paul Cornell

“Anger is just anger. It isn't good. It isn't bad. It just is. What you do with it is what matters. It's like anything else. You can use it to build or to destroy. You just have to make the choice."

Constructive anger," the demon said, her voice dripping sarcasm.

Also known as passion," I said quietly. "Passion has overthrown tyrants and freed prisoners and slaves. Passion has brought justice where there was savagery. Passion has created freedom where there was nothing but fear. Passion has helped souls rise from the ashes of their horrible lives and build something better, stronger, more beautiful.”
― Jim Butcher, White Night