Star Trek: The Original Series, Season 3

Kirk:
You said something about savagery, Mr. Flint. When was the last time you visited Earth?

Flint:
You would tell me that it is no longer cruel. But it is, Captain. Look at your starship. Bristling with weapons. Its mission to colonize, exploit, destroy if necessary to advance Federation causes.

Kirk:
Our missions are peaceful, our weapons defensive. If we were barbarians, we would not have asked for rytalin. Indeed, your greeting, not ours, lacked a certain benevolence.

Flint:
The result of pressures which are... not... your concern

Kirk:
Yes, well, those pressures are everywhere, in everyone, urging him to what you call savagery. The private hells, the inner needs and mysteries, the beast of instinct. As human beings, that is the way it is. To be human is to be complex. You can't avoid a little ugliness from within... and from without.