Ambrose Bierce
Marriage: The state or condition of a community consisting of a master, a mistress and two slaves, making in all, two.

Charles Darwin
Animals whom we have made our slaves we do not like to consider our equals. 

Albert Camus
A living man can be enslaved and reduced to the historic condition of an object. But if he dies in refusing to be enslaved, he reaffirms the existence of another kind of human nature which refuses to be classified as an object.

Albert Camus
The slave begins by demanding justice and ends by wanting to wear a crown. He must dominate in his turn.

John Adams
I have, through my whole life, held the practice of slavery in such abhorrence

John Adams
I shudder when I think of the calamities which slavery is likely to produce in this country.

John Adams
Slavery in this Country I have seen hanging over it like a black cloud for half a century…

Mother Teresa
Work without love is slavery.

Susan B. Anthony
The men and women of the North are slaveholders, those of the South slave-owners. The guilt rests on the North equally with the South.

Thomas Carlyle
Be not the slave of Words.