I love seeing the evolution of the series, which reflects how herge saw the world, as the evolution of how tintin sees the world. It's all black and white at first because tintin is The Good Guy according to the state propaganda he believes. He's serving the catholic colonial cause. He will get a good grade in journalism, something that is both normal to want and possible to achieve. He is in the right about everything and it makes sense for him to be right about everything because he wants to do good. He's not a Bad Person but as a direct result of his views he's the Main Character and colonial subjects are less than him. He can punch his way out of anything, even overpower the natural landscape (big game hunting in Congo)
But then as he is exposed to more perspectives and more experience the world becomes more ambiguous. Characters like alcazar and carreidas blur the black and white morality. Tintin is increasingly reliant on other characters and maybe he's not the sole Main Character anymore. (Compare how the public treat Tintin in Congo and America to the marlinespike cop not knowing who he is in calculus affair; this may not mean anything but I'm choosing to believe it does.) The knowledge that his antics puts his friends in danger and Maybe He Shouldn't Be Doing That has to be messy and confusing. Most importantly he can no longer Do Everything. Natural landscapes have power over him, especially in Tibet. He can't fix the complicated political problems of the world (the famous scenes with the slums in picaros). I just love how herge's character arc and the changes in the series overlaps with tintin becoming less of a Character and more of a Person over time. It's great.
