Your using the word dreadful do describe a perfect world. You are also using perfect.
Explanation:
Dreadfully means two things, one is very badly. Like the performers played the instruments dreadfully. The other is Extremely. Which would make sense in you case. And for the reason that perfect stands out is because there is no such thing as a perfect world. We are always going to make mistakes no matter what.
In that brief moment between life and death, perhaps Farquhar gains a look at some new level of reality: some perception that people can't see during life but that he is afforded a glimpse to in the moment of death