“As long as man is a slave to another power, he is not free to serve God with mature responsibility. He is not free to become what he is—human.”

Source: One is A Crowd: Reflections of An Individualist (1952), p. 47

IV, 3
Variant translation: The good man, though a slave, is free; the wicked, though he reigns, is a slave, and not the slave of a single man, but — what is worse — the slave of as many masters as he has vices.
The City of God (early 400s)
Context: The dominion of bad men is hurtful chiefly to themselves who rule, for they destroy their own souls by greater license in wickedness; while those who are put under them in service are not hurt except by their own iniquity. For to the just all the evils imposed on them by unjust rulers are not the punishment of crime, but the test of virtue. Therefore the good man, although he is a slave, is free; but the bad man, even if he reigns, is a slave, and that not of one man, but, what is far more grievous, of as many masters as he has vices; of which vices when the divine Scripture treats, it says, “For of whom any man is overcome, to the same he is also the bond-slave.”

The Reappearance of the Christ and the Masters of Wisdom (1980)

Being and Nothingness (1943)

Memoirs of J. Casanova de Seingalt (1894)

Source: Drenai series, Legend, Pt 1: Against the Horde, Ch. 15

Ah Yom
Lyrics, The Empyrean (2009)

Who Is a Free Man. What Is Freedom? http://parentingforeveryone.com/freeman/
Chelovek Svobodny (Free Man) (1994)

.
History of My Life (trans. Trask 1967), 1997 reprint, Preface, p. 26
Referenced