I'm pretty sure it's from the same episode as this one whose name escapes me ..
The Doctor couldn't explain it.
: So it's inexplicable. A miraculous non-
We haven't found the reason yet.
But of course you will. You'll find all the answers eventually, with enough time and study, and the right sort of tools. That's what you believe isn't it as a scientist?
Old Man 1
: Be honest.
Yes, that's what I've always
Old Man 2: Even when her science fails right before her eyes
she still has full confidence in it. Now there's a leap
Old Woman: Unconditional
trust. Now that's promising.