What theme is present in the following lines from Chapter 18 concerning the fight between the Shepherdsons and Grangerfords?
The boys jumped for the river- both of them hurt- and as they swum down the current the men run along the bank shooting at them and singing out, "Kill them, kill them!" It made me so sick I most fell out of the tree. I ain't agoing to tell all that happened- it would make me sick again if I was to do that. I wished I hadn't ever come ashore that night, to see such things. I ain't ever going to get shut of them- lots of times I dream about them.