Star Trek: The Original Series, Season 2

Kirk:
What I don't understand is how you were able to identify our counterparts so quickly.

Spock:
It was far easier for you as civilized men to behave like barbarians, than it was for them as barbarians to behave like civilized men. I assume they returned to their Enterprise at the same time you appeared here.

Kirk:
Probably. However, that Jim Kirk will find a few changes, if I read my Spocks correctly.

McCoy:
Jim, I think I liked him with a beard better. It gave him character. Of course, almost any change would be a distinct improvement.

Kirk:
What worries me is the easy way his counterpart fitted into that other universe. I always thought Spock was a bit of a pirate at heart.

Spock:
Indeed, gentlemen. May I point out that I had an opportunity to observe your counterparts here quite closely. They were brutal, savage, unprincipled, uncivilized, treacherous; in every way, splendid examples of homo sapiens, the very flower of humanity. I found them quite refreshing. [he returns to the science station]

Kirk:
I'm not sure, but I think we've just been insulted.

McCoy:
I'm sure.