Heyy im reading that right now! :)
The first two chapters reveal how human nature of the average person is very innocent and innately good, shown when Jack hesitates to kill the pig because he is scared.
If your talking about which one does not make sense then its the because its supposed to be "The"... i don't get your problem
This relates to unhealthy relationships cause now its caused an addiction as the rat only does it for pleasure over and over and over again.