The novel's title is a quote from a poem by the Irish poet W.B. Yeats called "The Second Coming": "Things fall apart; the center cannot hold; / Mere anarchy is loosed upon the world.” Much of the novel centers on Umuofia traditions of marriage, burial, and harvest. Achebe's decision to use a third-person narrator instead of writing the book from Okonkwo's perspective demonstrates just how central the idea of tradition is to the book, since the third-person narrator can more objectively describe facets of Umuofia society—their love of proverbs or how they make judicial decisions, for example—to the reader than Okonkwo could as an insider to these rituals. As the quote in the epigraph suggests, though, these traditions that form the center of Umuofia society cannot survive in the face of major changes occurring around them. As the white men enter the clans and impose their world order upon them, Umuofia society spirals apart.
Okonkwo and his son Nwoye also symbolize tradition and change, respectively. Okonkwo's character represents tradition, since he holds conventional ideas of rank, reputation, and masculinity in high esteem. As the book progresses, however, Okonkwo begins to fall out of favor with the clans, and his descent signals the crumbling of traditional Umuofia society. His adherence to tradition also drives him to kill his own surrogate son, Ikemefuna, driving away Nwoye in the process. Nwoye feels cold when he contemplates certain aspects of Umuofia society—such as leaving infant twins out to die and the idea of sacrificing innocents like Ikemefuna—and this pushes him to join the Christians when he's given the chance later in the novel.