Explain what Huck calls "conscience." How does it conflict with helping Jim escape?

Huck's conscience is his sense of guilt.... he wants to help Jim, but he also knows that in aiding Jim, he is going against what were cultural values or morals. Huck is talking to himself.... arguing with himself. He isn't so much worried about himself, he is worried about letting down the people who he believes expect better from him.

I couldn’t get that out of my conscience, no how nor no way. It got to troubling me so I couldn’t rest; I couldn’t stay still in one place. It hadn’t ever come home to me before, what this thing was that I was doing. But now it did; and it stayed with me, and scorched me more and more. I tried to make out to myself that I warn’t to blame, because I didn’t run Jim off from his rightful owner; but it warn’t no use, conscience up and says, every time, “But you knowed he was running for his freedom, and you could a paddled ashore and told somebody.” That was so—I couldn’t get around that noway. That was where it pinched. Conscience says to me, “What had poor Miss Watson done to you that you could see her nigger go off right under your eyes and never say one single word? What did that poor old woman do to you that you could treat her so mean? Why, she tried to learn you your book, she tried to learn you your manners, she tried to be good to you every way she knowed how. That’s what she done.”