He treated me with so much civility and consideration, while I was guilty of great rudeness
In this instance Ishmael acts savagely when he is supposed to be the civilized man and Queequeg acts in a civilized manner despite being labeled a savage. Melville, is making a statement on how fragile the divide between the savage and civilized is and how easily it is to go from one side to the other. It seems obvious, but remember that this is written before the Emancipation Proclamation.
To help improve the meaning of these lyrics, visit "Moby-Dick (Chap. 4: The Counterpane)" by Herman Melville and leave a comment on the lyrics box