TNG s3e16 “The Offspring”
The remainder of his speech:
You acknowledge their sentience, but you ignore their personal liberties and freedom. Order a man to hand his child over to the state? Not while I am his captain. If you wish, you can accompany us to Starfleet, where we shall see… [then Troi delivers the bad news]
Guinan neglected to mention the mating rituals of Klingons.