From: The Golden Sayings of Epictetus (translated by Hastings Crossley) - from Project Gutenberg.
CXXXVI
He is free who lives as he wishes to live; to whom none can do violence, none hinder or compel; whose impulses are unimpeded, whose desires are attain their purpose, who falls not into what he would avoid. Who then would live in error?—None. Who would live deceived and prone to fall, unjust, intemperate, in abject whining at his lot?—None. Then doth no wicked man live as he would, and therefore neither is he free.