McCoy: How does that Vulcan salute go? (Spock tries to demonstrate) That hurts worse than the uniform.
Amanda: After all these years among humans, you still haven't learned to smile.
Spock: Humans smile with so little provocation.
Amanda: You don't understand the Vulcan way, Captain. It's logical. It's a better way than ours. But it's not easy. It has kept Spock and Sarek from speaking as father and son for 18 years.
Kirk: Spock is my best officer... and my friend.
Amanda: I'm glad he has such a friend.
Sarek: Tellarites do no argue for reasons; they simply argue.
McCoy: Mrs. Sarek, I know about the rigorous training of the Vulcan youth, but tell me, did he ever run and play like the human children, even in secret ?
Amanda: Well, he, uh... he did have a pet sehlat he was very fond of.
Amanda: It's sort of a... a fat teddy bear.
McCoy: A teddy bear? A teddy bear.
Spock: Not precisely, Doctor. On Vulcan, the teddy bears are alive, and they have six-inch fangs.
Amanda: Sarek, you're proud of him, aren't you? You're showing almost human pride in your son.
Sarek: It does not require pride to ask that Spock be given the respect which is his due, not as my son, but as Spock.
Do you understand?
Amanda: Not really, but it doesn't matter. I love you anyway. I know. It isn't logical.
Gav: There will be payment for your slander, Sarek.
Sarek: Threats are illogical, and payment is usually expensive.
McCoy: Mrs. Sarek, you must understand the chances are extremely small to find a way to produce sufficient T-negative blood.
Spock: Indeed. I would estimate the odds...
Amanda: Please don't.
Spock: There is no logic in the attack on the Captain. There is no logic in Gav's murder.
Shras: Perhaps you should forget about logic, and devote yourself to motivation and passion again. Those are reasons for murder.
Amanda: When you were five years old and came home stiff-lipped, anguished, because the other boys tormented you saying that you weren't really Vulcan, I watched you knowing that... that inside... that the human part of you was crying... and I cried, too. There must be some part of me in you, some part that I still can reach. If being Vulcan is more important to you, then you'll stand there speaking rules and regulations from Starfleet and Vulcan philosophy and... and let your father die and... and I'll hate you for the rest of my life.
Chapel: Mr. Spock. Where do you think you're going ?
Spock: I must see the captain.
McCoy: My patients don't walk out on an operation.
Amanda: Oh, logic. I am so tired of hearing about your logic.
Spock: Emotional, isn't she?
Sarek: She has always been that way.
Spock: Indeed. Why did you marry her?
Sarek: At the time it seemed like the logical thing to do
McCoy: If you keep arguing with your kindly family doctor, you're going to spend your next 10 days right here. If you cooperate, you'll be out in two.
Spock: Doctor, I'll return to my station now.
McCoy: You are at your station.
Kirk: Dr. McCoy, I believe you're enjoying all this.
Spock: Indeed. I've never seen him look so happy.
McCoy: Shut up. Shh. Shh! Well, what do you know? I finally got the last word.