At the end of this selection of the book, the creature says "The sun is yet high in the heavens, before it descends to hide itself behind your snowy precipices and illuminate another world, you will have heard my story and can decide. On you it rests, whether I quit forever the neighbourhood of man and lead a harmless life, or
become the scourge of your fellow creatures and the author of your own speedy ruin."
This is an example of

1.rhetoric
2.indirect foreshadowing
3.direct foreshadowing
4.symbolism

Symbolism because it is representing some thing when it says the sun is yet high in the heavens that mean heaven is above

"Living to ideal ends without any mixture of self-indulgence lowers the value of benevolent and thoughtful men we know" 
"Refusing luxuries, simply as unfit for his habit; quiet and gentle as a child in the house"
-These lines are an attempt by Emerson to portray Brown as an everyman, that slaves can associate to. Brown has been exposed to the perils that slaves are subjected to when he saw their harsh realities as a child. This positions Brown as a relatable fellow amidst of being convicted for the violence behind his anti-slavery movement.
Emerson is a supporter of non-violence and is a surprising supporter of Brown. There is an aspect of Brown that he tries to bring to the surface. Emerson wants Brown's good intentions and motives so as to remove the spotlight on the main point of the movement.