Related:

• In every revolution, there's one man with a vision. -- Kirk, "Mirror, Mirror," stardate unknown.
• Conquest is easy. Control is not. -- Kirk, "Mirror, Mirror," stardate unknown.
• No one may kill a man. Not for any purpose. It cannot be condoned.
  -- Kirk, "Spock's Brain," stardate 5431.6....
• Of all forces acting on man, change is the most beneficial and the most cruel.
• No one can guarantee the actions of another. -- Spock, "Day of the Dove," stardate unknown.
• Man: We want you to tell us what you think. And, be honest, because no one from the show is here spying on you.
  [chuckles] [a sneezing sound comes from a huge mirror set along a wall of the room...
• Are you sure you won't change your mind? Is there something wrong with the one I have?
  -- Gillian & Spock, "The Voyage Home," stardate 8390....
• Spock: "In any case, were I to invoke logic, logic clearly dictates that the needs of the many outweigh the needs of the few.
  Kirk: "Or the one." -- "STII:TWOK", Stardate 8130.4...
• Spock: "I do not dispute that in the wrong hands--" McCoy
  'In the wrong hands'? Would you mind telling me whose are the right hands, my logical friend?...