Barrows: All right, but you stay right there. Don’t peek.
McCoy: My dear girl, I am a doctor. When I peek, it’s in the line of duty.
Star Trek – Season 1: Episode 17 – “Shore Leave”
Spock: I picked this up from Doctor McCoy’s log. We have a crew member aboard who’s showing signs of stress and fatigue. Reaction time down nine to twelve percent, associational reading norm minus three.
Kirk: That’s much too low a rating.
Spock: He’s becoming irritable and quarrelsome, yet he refuses to take rest and rehabilitation. Now, He has that right, but we’ve found
Kirk: A crewman’s right ends where the safety of the ship begins. That man will go a shore on my orders. What’s his name?
Spock: James Kirk. Enjoy yourself, Captain.
Star Trek – Season 1: Episode 17 – “Shore Leave”
McCoy: Well, I had to see it to believe it.
Spock: Explain.
McCoy: They’re about to lop off the captain’s professional head, and you’re playing chess with the computer.
Spock: That is true.
McCoy: Mr. Spock, you’re the most cold-blooded man I’ve ever known.
Spock: Why, thank you, Doctor.
Star Trek – Season 1: Episode 14 – “Court Martial”
Spock: Nothing, Captain. No contacts, no objects in any direction.
Kirk: Care to speculate on what we’ll find if we go on ahead?
Spock: Speculate? No. Logically, we’ll discover the intelligence which sent out the cube.
Kirk: Intelligence different from ours or superior?
Spock: Probably both, and if you’re asking the logical decision to make
Kirk: No, I’m not. The mission of the Enterprise is to seek out and contact alien life.
Spock: Has it occurred to you that there’s a certain inefficiency in constantly questioning me on things you’ve already made up your mind about?
Kirk: It gives me emotional security.
Star Trek – Season 1: Episode 2 – “The Corbomite Maneuver”
Bailey: Raising my voice back there doesn’t mean I was scared or couldn’t do my job. It means I happen to have a human thing called an adrenaline gland.
Spock: It does sound most inconvenient, however. Have you considered having it removed?
Bailey: Very funny.
Sulu: You try to cross brains with Spock, he’ll cut you to pieces every time.
Star Trek – Season 1: Episode 2 – “The Corbomite Maneuver”

Kirk: You could see the alarm lights flashing from there, McCoy. Why didn’t you tell me?
Bones: Finally finished a physical on you, didn’t I. (Kirk leaves) What am I, a doctor or a moon shuttle conductor? If I jumped every time a light came on around here, I’d end up talking to myself.
Star Trek – Season 1: Episode 2 – “The Corbomite Maneuver”