“The least important things, sometimes, my dear boy, lead to the greatest discoveries.”

 - The First Doctor, The Space Museum (1965)

“We’re all capable of the most incredible change. We can evolve while still staying true to who we are. We can honour who we’ve been and choose who we want to be next. Now’s your chance! How about it?”

“Never give up. Never give in.”

“Every great decision creates ripples, like a huge boulder dropped in a lake. The ripples merge, rebound off the banks in unforeseeable ways. The heavier the decision, the larger the waves, the more uncertain the consequences.”

"Logic, my dear Zoe, merely enables one to be wrong with authority."

 - The Second Doctor, The Wheel in Space (1968)

“There’s always something to look at if you open your eyes.”

 - The Fifth Doctor, Kinda (1982)

“A straight line may be the shortest distance between two points, but it is by no means the most interesting.”

“The way I see it, every life is a pile of good things and bad things. Hey. 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.”

“Small though it is, the human brain can be quite effective when working at full efficiency.”

“Do you know what thinking is? It’s just a fancy word for changing your mind.”

“Some people live more in 20 years than others do in 80. It’s not the time that matters. It’s the person.”

“The very powerful and the very stupid have one thing in common. They don’t alter their views to fit the facts, they alter the facts to fit their views.”

“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.”