Letter 80 is a rich storehouse of all the themes of the novel. The three most significant themes discussed are male and female relationships, African and black American relationships, and personal independence.
Concerning the second of these themes, you should be aware that Samuel and Nettie (now that Corrine is dead) are good missionaries, but they have no sense of place; they don't belong. They belong neither to the world of the European power structure nor to the traditional world of the black West African. They belong only to God and to one another. In the world of growing avarice and exploitation that is encroaching into the jungle, they are powerless. Samuel is disappointed that the Olinka never recognized them as blood brother and sister. In fact, the Olinka reject Samuel and Nettie, suspicious of their rejection of America's "progress" — motorcars, for example.
Had Samuel and Nettie not have gotten married, they both may have ended up feeling completely unappreciated. Samuel's character has the distinction of being the only accepting, loving, and giving husband in the entire novel.
The mention of "DuBoyce" in this letter is important. Nettie is actually discussing the great black American sociologist, philosopher, and civil rights leader, W. E. B. Du Bois, who was born in 1868 and died in 1963 in Ghana, West Africa. As a noted scholar, he tried to create an appreciation of black Americans, and he was instrumental in founding the National Association for the Advancement of Colored People (NAACP). He and Booker T. Washington, the founder of Tuskegee Institute in Tuskegee, Alabama, had a heated debate over the method by which blacks should advance. Washington stressed a practical economic freedom that would in time lead to a political and cultural freedom. Washington wanted blacks to get jobs as postal workers, carpenters, and repairmen. On the other hand, Du Bois wanted blacks to aspire to become professionals. His Harvard education made him fiercely defend the position that knowledge was the most important thing a man could acquire.
