I can't remember her name, but she was well known in the underground railway.

She carried a pistol, not because she was particularly in danger from the law, but from the slaves she was helping to set free.

Many of them could not leave their shackles behind, even though, physically, they were without chains.

This is quite the proof that slavery is in the mind.
And, that it is a choice.

Further, "To educate a man is to make him unfit to be a slave".