This is the interesting part of the novel and maybe the most important issue of slavery: that through their acts, slave people proved that they are also human beings like whites, and they wanted freedom from all points of view.
So, Nightjohn was not thinking only to himself, he realized that his acts could release the slaves.But Nightjohn did not see freedom in a war, or he did not want for him and his people the white's money. Slave people understood differently the slavery. They wanted rights which could allow them to learn, to travel, to feel themselves free people. Money is not important at all for a man that stays withdrawn like a bird.
Nightjohn finds a different way of liberation: words. This thing comes from the fact that slavers were forbidden to read and to write. They had to communicate their feelings in other ways, and not to be seen of their master.
It is a mean treatment because even birds from a cage can speak on their language . So, Nightjohn sees liberation in words, and we can extent, in education. "Words are freedom, old man. Cause that's all that slavery's made of :words. Laws, deeds, passes: all they are is words. White folks got all the words , and they mean to keep them. You get some words for yourself and you bee free!"(qtd. Night John)
Words may be a symbol for freedom, but they also may express a symbol for ...