Star Trek Season 2 Episode 25

McCoy: Quite logical, I'd say, Just as it's logical that a 20th-century Rome would use television to show its gladiator contests or name a new car the Jupiter 8.
Spock: Doctor, if I were able to show emotion, your new infatuation with that term would begin to annoy me.
McCoy: What term? Logic? Medical men are trained in logic, Mr. Spock.
Spock: Really, Doctor, I had no idea they were trained. Watching you, I assumed it was trial and error.