"This thing becomes wife, lover, best friend, wise man, fool, idol, slave.
It isn't bad to have everyone in the universe at your beck and call.
You win all the arguments."
"You go slow, be gentle.
It's no one-way street -- you know how you feel and that's all.
It's how the girl feels too. Don't press.
If the girl feels anything for you at all, you'll know."
Where No Man Has Gone Before
"You heard the mathematics of it. In a month, he'll have as much in common with us as we'd have with a shipful of white mice."
The Naked Time
"Instruments register only those things they're designed to register.
Space still contains infinite unknowns."
The Enemy Within
"We all have our darker side.
We need it; it's half of what we are.
It's not really ugly, it's human."
"The sound of male ego.
You travel halfway across the galaxy, and it's still the same song."
What Are Little Girls Made Of?
"Programming. Different word, but the same old promises made by Genghis Khan, Julius Caesar, Hitler, Ferris, Maltuvis."
"Eternal childhood, filled with play, no responsibilities.
It's almost like a dream."
Dagger of the Mind
"Where there's no emotion, there's no motive for violence."
The Corbomite Maneuver
" You know the greatest danger facing us is ourselves, an irrational fear of the unknown.
But there's no such thing as the unknown-- only things temporarily hidden, temporarily not understood."
Episode 11 & 12
"A man either lives life as it happens to him, meets it head-on, and licks it.
Or he turns his back on it and starts to wither away"
The Conscience of the King
"Do you play God, carry his head through the corridors in triumph?
That won't bring back the dead, Jim."
Balance of Terror
"In a different reality, I could have called you friend.
"A crewman's rights end where the safety of the ship begins."
The Galileo Seven
"Life and death are seldom logical."
The Squire of Gothos
"I object to intellect without discipline. I object to power without constructive purpose."
"Your violent intent and actions demonstrate that you are not civilized."
Tomorrow Is Yesterday
"The truth is, I'm a little green man from Alpha Centauri, a beautiful place. You ought to see it."
"They're about to lop off the captain's professional head, and you're playing chess with the computer."
The Return of the Archons
"I am Landru. I am he. All that he was I am, his experience, his knowledge."
"It has been said that social occasions are only warfare concealed."
A Taste of Armageddon
"Death. Destruction. Disease. Horror.
That's what war is all about.
That's what makes it a thing to be avoided."
This Side of Paradise
"What can you expect from a simpering, devil-eared freak, whose father was a computer and his mother an encyclopedia?"
The Devil in the Dark
"Either one of us by himself is expendable. Both of us are not."
Errand of Mercy
"Curious how often you Humans manage to obtain that which you do not want."
The Alternative Factor
"Are you deaf as well as blind?!"
The City on the Edge of Forever
"They will be able to find a way to give each man hope and a common future and those are the days worth living for."
"Pain is a thing of the mind. The mind can be controlled."