For Frederick, Mrs. Auld was described as a “pious, warm, and tender-hearted woman.” (Frederick) and taught the him how to read and write rather than leaving him a sense of condescending. But under the influence of slavery for some time, her tender heart became stone and finally became even more “violent in her opposition than her husband himself.” Here, the author himself not only felt inferior, but also a sense of regret that the slavery made such a kind women become a bad-tempered slave owner. As to him, the most terrible influence of slavery was not the physical harm to the slaves but the imprisonment of people's thoughts (including two aspects of the slave and the slave owner). For salves, just as what Mr. Auld said, they were required