On my travels to Cathay, Ian, I have come to believe many things I'd previously doubted. For instance, when I was a boy in Venice, they told me that in Cathay there was a stone that burned. I did not believe, but there is such a stone: I have seen it. And if stone burns, why not a caravan that flies? Birds fly; I have even seen fish that fly. You are asking me to believe that your caravan can defy the passage of the sun? Move not merely from one place to another, but from today into tomorrow, today to yesterday? No Ian, that I cannot believe.
The Time Lords are an immensely civilised race. We can control our own environment - we can live forever, barring accidents, and we have the secret of space-time travel.
Homo sapiens. What an inventive, invincible species. It's only a few million years since they crawled up out of the mud and learned to walk. Puny, defenceless bipeds. They've survived flood, famine and plague. They've survived cosmic wars and holocausts. And now, here they are, out among the stars, waiting to begin a new life. Ready to outsit eternity. They're indomitable.
Look at me. No plans, no backup, no weapons worth a damn. Oh, and something else I don't have: anything to lose. So, if you're sitting up there with your silly little spaceships and your silly little guns and you've any plans on taking the Pandorica tonight; just remember who's standing in your way. Remember every black day I ever stopped you and then, and then, do the smart thing. Let somebody else try first.
Let me tell you something about the human race. You put a mysterious blue box slap-bang in the middle of town, what do they do? Walk past it. Now stop your nagging. Let's go and explore.
'Cause that's how I see the universe. Every waking second, I can see what is, what was, what could be, what must not. That's the burden of a Time Lord, Donna. And I'm the only one left.