Kirk: Then what is it?
The Guardian: A question. Since before your sun burned hot in space and before your race was born, I have awaited a question.
Kirk: What are you?
The Guardian: I am the Guardian of Forever.
Kirk: Are you machine or being?
The Guardian: I am both and neither. I am my own beginning, my own ending.
Spock: I see no reason for answers to be couched in riddles.
The Guardian: I answer as simply as your level of understanding makes possible.
Spock: A time portal, Captain--a gateway to other times and dimensions, if I'm correct.
The Guardian: As correct as possible for you. Your science knowledge is obviously primitive.
Kirk: Annoyed, Spock?