• "The Universe is big. It's vast and complicated and ridiculous. And sometimes—very rarely—impossible things just happen and we call them miracles."
• “This is one corner… of one country, in one continent, on one planet that’s a corner of a galaxy that’s a corner of a universe that is forever growing and shrinking and creating and destroying and never remaining the same for a single millisecond. And there is so much, so much to see.” 7x4
• "The way I see it, every life is a pile of good things and bad things. The good things don't always soften the bad things, but vice-versa, the bad things don't necessarily spoil the good things and make them unimportant." ― Vincent and the Doctor
• "Some people live more in 20 years than others do in 80. It’s not the time that matters, it’s the person." ― The Lazarus Experiment
• "We all change, when you think about it. We’re all different people all through our lives. And that’s okay, that’s good, you’ve got to keep moving, so long as you remember all the people that you used to be. I will not forget one line of this. Not one day. I swear. I will always remember when the Doctor was me." – The Time Of The Doctor
• "Clara: Listen. This is just a dream. But very clever people can hear dreams. So please just listen. I know you’re afraid, but being afraid is all right. Because didn’t anybody ever tell you? Fear is a superpower. Fear can make you faster, and cleverer, and stronger. And one day, you’re gonna come back to this barn, and on that day, you’re going to be very afraid indeed. But that’s okay. Because if you’re very wise and very strong, fear doesn’t have to make you cruel or cowardly. Fear can make you kind. … It doesn’t matter if there’s nothing under the bed, or in the dark, so long as you know it’s okay to be afraid of it. So listen. If you listen to nothing else, listen to this: you’re always going to be afraid, even if you learn to hide it. Fear is like… a companion. A constant companion, always there. But that’s okay. Because fear can bring us together. Fear can bring you home. I’m gonna leave you something just so you’ll always remember. Fear makes companions of us all." listen
• "Let me tell you about scared. Your heart is beating so hard, I can feel it through your hands. There's so much blood and oxygen pumping through your brain, it's like rocket fuel. Right now, you could run faster and you can fight harder, you could jump higher than ever in your life. And you're so alert, it's like you can slow down time. What's wrong with scared? Scared is a super power. It's your super power. There is danger is this room, and guess what? It's you! You feel it?" listen
• Wilfred: "Nine hundred years. We must look like insects to you." The Doctor: "I think you look like giants." – The End of Time pt. 2
• “People assume that time is a strict progression of cause to effect, but *actually* from a non-linear, non-subjective viewpoint - it's more like a big ball of wibbly wobbly... time-y wimey... stuff.”
• "The thing is, Adam, time travel is like visiting Paris. You can't just read the guidebook, you've got to throw yourself in. Eat the food, use the wrong verbs, get charged double and end up kissing complete strangers. Or is that just me?"
• "You want weapons? We're in a library. Books are the best weapon in the world. This room's the greatest arsenal we could have. Arm yourself!" - Tooth and Claws
• “When you’re a kid, they tell you it’s all… Grow up, get a job, get married, get a house, have a kid, and that’s it. But the truth is, the world is so much stranger than that. It’s so much darker. And so much madder. And so much better.” 2x10
• “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. 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.” 6x13
• "You know when sometimes you meet someone so beautiful — and then you actually talk to them and five minutes later they're as dull as a brick; but then there's other people. And you meet them and you think, "Not bad, they're okay," and when you get to know them ... their face just, sort of, becomes them, like their personality's written all over it, and they just — they turn into something so beautiful. Rory's the most beautiful man I've ever met." the girl who waited
• “We’re all stories, in the end. Just make it a good one, eh?” 5x13
• "This is a scale model of war! Every war ever fought, right there in front of you! Because it's always the same! When you fire that first shot, no matter how right you feel, you have no idea who's going to die! You don't know whose children are going to scream and burn. How many hearts will be broken! How many lives shattered! How much blood will spill until everybody does what they were always going to have to do from the very beginning: SIT!! DOWN!! AND!! TALK!!" - The Zygon Inversion
• “I am and always will be the optimist. The hoper of far-flung hopes and the dreamer of improbable dreams.”6

"Argh! The Brothers Grimm, lovely fellas.They're on my darts team. Argh! According to them, there's this emperor and he asks this shepherd's boy, "How many seconds in eternity?" [20 million years later] And the shepherd's boy says, "There's this mountain of pure diamond. It takes an hour to climb it, and an hour to go around it!" [52 million years later] Every hundred years, a little bird comes and sharpens its beak on the diamond mountain. [Nearly a billion years later] Argh! And when the entire mountain is chiselled away, the first second of eternity will have passed! [Well over a billion years later] Argh! You must think that's a hell of a long time... [After a total of about 4.5 billion years] Personally, I think that's a hell of a bird."- Heaven Sent