DOCTOR: Human progress isn't measured by industry, it's measured by the value you place on a life. An unimportant life. A life without privilege. The boy who died on the river, that boy's value is your value. That's what defines an age. That's what defines a species.

BILL: If you care so much, tell me how many people you’ve seen die?

DOCTOR: I don’t know.

BILL: Yeah? How many before you lost count?

DOCTOR: I care, Bill, but I move on.

DOCTOR: I am two thousand years old and I have never had the time for the luxury of outrage.