McCoy: Well, you must be very unhappy, Mr. Spock.
Spock: That is a human emotion, doctor, with which I am totally unfamiliar. How could I be unhappy?
McCoy: Well, we found a whole world of minds that worked just like yours. Logical, unemotional, completely pragmatic. And we poor, irrational humans whipped them in a fair fight. Now you'll find yourself back among us illogical humans again.
Spock: Which I find eminently satisfactory, doctor. For nowhere am I so desperately needed as among a shipload of illogical humans.