Citizen of the Galaxy...

...one of many books I enjoyed years ago. One of Heinlein juveniles on the topics of slavery, responsibility and citizenship.

First edition cover (https://en.wikipedia.org/wiki/Citizen_of_the_Galaxy)

"A wise man could not be insulted, since truth could not insult and untruth was not worthy of notice."

Colonel Brisby had once said, about Pop: "It means being so devoted to freedom that you are willing to give up your own . . . be a beggar . . . or a slave . . . or die -- that freedom may live."

"Give your mind a rest and use your eyes instead. There's a time and place for everything."

"You're right, Jim."

"Goodnight, son," the old beggar whispered. "Good dreams . . . and good luck!"