Tom idiotically revels in his wound, which he thinks is fun and exciting. It was his plan that endangered his friends and got him shot, and it’s because he got shot that Jim feels duty-bound to risk his own freedom by staying with Tom. Huck’s comment that Jim is white inside at once acknowledges Jim’s equality, but also insidiously suggests that people who are “black inside,” so to speak, are bad. Huck is able to see past society's rules to see Jim's basic humanity, but he still accepts his society's larger social laws that to be human means to be white. This dichotomy strikes the reader as ridiculous—the reader can generalize from the fact of Jim's basic humanity to all slave's basic humanity. Twain uses Huck's inability to do the same to actually underscore the point, and further condemn Southern society for its cruel, ridiculous blindness.