Leonard Nimoy: Spock
McCoy : [Kirk runs in to the engine room and sees Spock inside the reactor compartment. He rushes over but McCoy and Scotty hold him back] No! You'll flood the whole compartment!
Kirk : He'll die!
Scotty : Sir! He's dead already.
McCoy : It's too late.
[They let go and Kirk walks to the glass and pushes the intercom button]
Kirk : Spock!
[Spock slowly walks over to the glass and pushes the intercom]
Spock : The ship... out of danger?
Kirk : Yes.
Spock : Do not grieve, Admiral. It is logical. The needs of the many, outweigh...
Kirk : The needs of the few.
Spock : Or the one. I never took the Kobayashi Maru test until now. What do you think of my solution?
Kirk : Spock.
[Spock sits down]
Spock : [Gasping] I have been... and always shall be... your friend.
[he places a Vulcan salute on the glass]
Spock : [Gasping] Live long... and prosper.
Kirk : No.
Spock : [closing monologue] Space: the final frontier. These are the continuing voyages of the starship Enterprise. Her ongoing mission: to explore strange new worlds, to seek out new life forms and new civilizations, to boldly go where no man has gone before.
[On whether Kirk should assume command from Spock]
Spock : If I may be so bold, it was a mistake for you to accept promotion. Commanding a starship is your first, best destiny; anything else is a waste of material.
Kirk : I would not presume to debate you.
Spock : That is wise. Were I to invoke logic, however, logic clearly dictates that the needs of the many outweigh the needs of the few.
Kirk : Or the one.
Spock : You are my superior officer. You are also my friend. I have been and always shall be yours.
[Discussing the effects of the Genesis torpedo]
McCoy : Dear Lord. You think we're intelligent enough to... suppose... what if this thing were used where life already exists?
Spock : It would destroy such life in favor of its new matrix.
McCoy : Its "new matrix"? Do you have any idea what you're saying?
Spock : I was not attempting to evaluate its moral implications, Doctor. As a matter of cosmic history, it has always been easier to destroy than to create.
McCoy : Not anymore; now we can do both at the same time! According to myth, the Earth was created in six days. Now, watch out! Here comes Genesis! We'll do it for you in six minutes!
Spock : Really, Dr. McCoy. You must learn to govern your passions; they will be your undoing. Logic suggests...
McCoy : Logic? My God, the man's talking about logic; we're talking about universal Armageddon! You green-blooded, inhuman...
Spock : He is intelligent, but not experienced. His pattern indicates two-dimensional thinking.
Joachim : [Enterprise is running with shields down] They still haven't raised their shields.
Khan : Raise ours.
[Joachim raises shields]
Spock : Their shields are going up.
Khan : Lock phasers on target.
Joachim : [looks at targeting computer] Locking phasers on target.
Spock : They're locking phasers.
Kirk : Raise shields!
Khan : Fire!
[Joachim fires phasers]
Spock : You proceed from a false assumption. I am a Vulcan. I have no ego to bruise.
Kirk : Kirk to Enterprise.
Spock : Spock here.
Kirk : Captain Spock, damage report.
Spock : Admiral, if we go "by the book". like Lieutenant Saavik, hours could seem like days.
Kirk : I read you captain. Let's have it.
Spock : The situation is grave, Admiral. We won't have main power for six "days". Auxiliary power has temporarily failed. Restoration may be possible, in two "days". By the book, Admiral.
Kirk : Meaning you can't even beam us back?
Spock : Not at present.
Kirk : Captain Spock, if you don't hear from us within one hour, your orders are to restore what power you can, take the Enterprise to the nearest star base, and alert Starfleet Command as soon as you're out of jamming range.
Commander Nyota Uhura : Sir, we won't leave you behind!
Kirk : Uhura, if you don't hear from us, there won't be anybody behind. Kirk out.
Spock : We are now in violation of treaty, Captain.
McCoy : [grabbing Spock's arm] You're not going in there!
Spock : Perhaps you're right. What is Mr. Scott's condition?
McCoy : [turns to Scotty] Well I don't think that he...
[Spock use the vulcan nerve pinch on McCoy]
Spock : I'm sorry, Doctor, I have no time to explain this logically.
[sits McCoy down and performs mind meld]
Spock : Remember!
Spock : for everything; there is a first time. don't you agree admiral?