I have just answered a very similar question concerning Stephen Kumalo, so instead of focusing on him again, I will look at the character of James Jarvis. One of the important stylistic aspects of this novel is how Kumalo´s journey is paralleled with that of Jarvis - both leave their homes in the countryside and go to the city of Johannesburg, where they have to confront certain realities about themselves, their family and their country that change them irrevocably and "enlighten" them, making them wiser characters that want to be part of making their country a better place. A really interesting question would be to compare both of these characters and the "journeys" they undergo.
One key difference between them of course is that Jarvis never has an opportunity to meet his son again, though of course, in the course of the novel, both of these key characters lose their sons. However, arguably, Jarvis is allowed to "meet" his son, if not physically, then through his writing and the ideas that he championed about the problem of South Africa. Jarvis starts off as a white, English speaking farmer whose farm is situated on the good land that the tribe of Ndotsheni do not have access too. Jarvis, like many of his contemporaries, doesn´t really care or know much about the rampant division and injustice within South Africa. He appears to merely focus on his family and his job, not being aware of how the political system which governs his life favours him over others.
However, this attitude is destroyed irrevocably with the news of the death of his son. His journey to Johannesburg allows him to know his son in a way that he has never before known him. He discovers the position of authority that Arthur had gained in the community and an important orator for social justice. Jarvis realises with a chilling realisation that his son had become a stranger to him:
Jarvis filled his pipe slowly, and listened to this tale of his son, to this tale of a stranger.
Trying to understand his son, Jarvis reads his writings concerning South Africa and Arthur´s perception of them. He is moved and inspired by his son´s work, and is "enlightened" through reading them. These writings appear to give Jarvis a moral awakening, and he returns to his farm determined to try to make things better for the people in the village, by, for example, supplying milk to the children and employing an agriculturist. He commits himself to fulfilling the last wish of his wife before she dies - to rebuild the church in Ndotsheni. Thus, although he is a man of few words he expresses himself through his actions and his commitment to making a difference, whatever the cost to himself, is moving.