James T. Kirk: Now, what is it with you, Spock? Hm? Your planet was just destroyed, your mother murdered, and you're not even upset!
Spock: If you are presuming that these experiences in any way impede my ability to command this ship, you are mistaken.
James T. Kirk: And yet you were the one who said fear was necessary for command. I mean, did you see his ship? Did you see what he did?
Spock: Yes, of course I did.
James T. Kirk: So are you afraid or aren't you?
Spock: I will not allow you to lecture me about the merits of emotion.
James T. Kirk: Then why don't you stop me?
Spock: Step away from me, Mister Kirk.
James T. Kirk: What is it like not to feel anger... or heartbreak... or the need to stop at nothing to avenge the death of the woman who gave birth to you?
Spock: Back away from me.
James T. Kirk: You feel NOTHING! It must not even COMPUTE for you! You NEVER loved her!
[Spock snaps and attacks Kirk, nearly killing him]
[Spock regains control]