Once

"What of them? Shall I destroy them?"
"Then they will learn nothing."
"A most interesting conclusion. But what if they never learn, Riker?"
"Is this a test also?"
"Hmm. In life, one is always tested."
"I see them much as we were several hundred years ago; but possessing the technology they now have, they're very dangerous.... But we can hardly hate what we once were. They may grow, and learn."
"And learn ways to destroy you?"
"Well, our values require us to face that possibility."

- Commander Riker and Portal in Star Trek: The Next Generation - 1x05 - The Last Outpost

Justice

The question of justice has concerned me greatly of late, and I say to any creature that may be listening, there can be no justice as long as laws are absolute. Even life itself is an exercise in exceptions.

- Captain Jean-Luc Picard in Star Trek: The Next Generation - 1x08 - Justice

Separate

"That space and time and thought aren't the separate things they appear to be? I just thought the formula you were using said something like that."
"Boy, don't ever say that again, especially at your age, in a world that's not ready for such...such dangerous nonsense."

- Wesley Crusher and The Traveller - Star Trek: The Next Generation - 1x06 - Where No One Has Gone Before

Extreme

We humans tend to take a rather balanced approach towards life -- never too much, never too little. And it's very nice to find a culture that is willing to take an experience to its furthest extreme.

- Captain Jean-Luc Picard in Star Trek: The Next Generation - 7x02 - Liaisons

Please You

A famous monk once said, "I don't always know what to do, my lord, but I think the fact that I want to please you pleases you."

- Isaac Jaffey in Sports Night - 2x08 - The Reunion