Stowe uses this dialogue between George and Haley to illustrate that slavery is unethical in every circumstance by showing that there are two parts involved who are equally as guilty for the problem.
George criticizes Haley for selling men and women but at the same time buys slaves himself. George knows that slavery is wrong and does not approve of it. However, he still participates and helps the system to keep standing by buying people to work for him.
With this, the author seeks to convey the idea that it is not only selling slaves that is unethical, but also buying them.
Ok, so I'm going to try my best to answer this.
My best guess would be how he said that he was able to see his answer through whoever he is talking to, then lose it again. He understood and got something, then lost it's understanding. I sincerely hope this helps.. I'm sorry I'm not very good at explaining. ^^;
To highlight a character's (usually the protagonist's) personality, the introduction of a foil is used. In Shakespeare's 'Hamlet', Laertes is Hamlet's foil. They were childhood friends but have completely opposite traits and behaviors: Hamlet is verbal, he ponders, and is driven by passionate inaction, Laertes is physical, blusters, and is driven by passionate action.
In Act IV, scene V, we can see Laerts personality; he bursts and needs people to calm him down, whereas Hamlet would have stayed calm and think before acting.
The central idea is the same as the main idea. Most of the time, the main idea is mentioned in the Title. Without reading the essay, I do not know what the central/main idea is.
