"If I were asked what strikes me as the greatest evil inflicted by slavery I should say, it is the outrage offered by slavery to human nature. Slavery does all that lies in human power to unmake men, to rob them of their humanity, to degrade men into brutes; and this it does by declaring them to be Property. Here is the master evil. Declare a man a chattel, something which you may own and may turn to your use, as a horse or a tool; strip him of all right over himself, of all right to use his own powers, except what you concede to him as a favor and deem consistent with your own profit; and you cease to look on him as a man. You may call him such; but he is not to you a brother, a fellow-being, a partaker of your nature and your equal in the sight of God. You view him, you treat him, you speak to him, as infinitely beneath you, as belonging to another race. You have a tone and a look towards him which you never use towards a Man. Your relation to him demands that you treat him as an inferior creature. You cannot, if you would, treat him as a Man. That he may answer your end, that he may consent to be a slave, his spirit must be broken, his courage crushed; he must fear you. A feeling of his deep inferiority must be burnt into his soul. The idea of his rights must be quenched in him by the blood of his lashed and lacerated body. Here is the damming evil of slavery; it destroys the spirit, the consciousness of a man. 

I care little, in comparison, for his hard outward lot, his poverty, his unfurnished house, his coarse fare; the terrible thing in slavery is the spirit of a slave, the extinction of the spirit of a man. He feels himself owned, a chattel, a thing bought and sold, and held to sweat for another's pleasure at another's will, under another's lash, just as an ox or horse. Treated thus as a brute, can he take a place among men? A slave! Is there a name so degraded on earth, a name which so separates a man from his kind? And to this condition millions of our race are condemned in the land of liberty."  William Ellery Channing.