Because Huckleberry Finn is told from Huck's point of view, the reader is able to see Huck's thoughts on everything that happens to him. Throughout the novel, Huck is constantly faced with decisions to make. It is when faced with these decisions that Huck explores his conscience in order to figure out how to do what is right. As a young white boy living in the South during very racist times, he has been raised to think a certain way. His battles with his conscience show that he knows what he is supposed to think, but this is in conflict with what he truly believes is right.
Sometimes, Huck even goes against what society has told him is right and in this way he thinks he is doing something wrong. He can't really decide in these times what his conscience is telling him because he cannot tell the difference between his conscience and society. From the beginning of his adventure with Jim, Huck is very confused about what is right and wrong. When promising Jim that he won't turn him in, he says
I said I wouldn't, and I'll stick to it. Honest INJUN, I will. People would call me a low-down Abolitionist and despise me for keeping mum – but that don't make no difference. I ain't a-going to tell, and I ain't a-going back there, anyways. So, now, le's know all about it.
When he says that people would call him a "low-down Abolitionist" for keeping quiet, he is assuming that he is doing the wrong thing by not turning Jim in. As readers, we know that Huck is actually doing the right thing. We know that slavery is wrong and that Jim deserves to be free, but because Huck is breaking the law, he actually thinks he is doing something wrong. He has similar battles with his conscience throughout. Any time he says or does something to keep Jim safe, he sees it as a weakness rather than a strength, because he genuinely thinks he is doing something wrong.