The irony of church and state
Because of modern language, most people today are familiar with the reasons why church interests and state interests are best left separated. Church and state operate with two separate sources of power, and both are political—meaning derived from the participation of everyone at once. In this book, they are entangled; the Prime Minister appoints a bishop and confuses the local religious economy. The reasons that are well understood as to why this kind of entanglement is not productive are locked in dramatic irony as the characters gradually come to similar opinions.
The ironic wife
This Bishop Proudie fellow has a wife that just won't let him have peace of mind. Instead of the traditional, patriarchal symbolism of the perfect wife as a true supporter of the estate, instead of a "helper," this Bishop is given a woman who could be defined by another Bible verse as "naggy." What is the symbolic relevance of this terrible irony? It symbolizes the real world complications that life contains and their effect on a minister who is desperately trying to operate in a heavenly manner. She is a symbol for fate's way of obfuscating the holy path in life, a femme fatale.
The threat of a young female
Another valuable character-symbol is found in Mr. Slope whose name implies that he looks down on people. The young Stanhope girl who threatens him completes a symbolic image of a patronizing man realizing the threat of a powerful woman. A powerful woman is a threat to his very perception of reality. Another aspect of this symbolic dynamic will help clarify this; she is young and he is old. That means that she bears an inherent threat of eventual supersession, which is a major theme of the novel as well. He cannot ignore her power; that is what is symbolized by the threat.
The desired daughter
Dr. Vesey Stanhope has his hands full in this novel for sure. He is a symbolic plate spinner, an expert in responsibility whose vices involve over-activity, not lethargy or drunkenness. His major flaw is that he stifles others to attain a more consistent emotional stability; in other words, he exerts orderly control which is productive but also repressive. His daughter Eleanor is a symbol for his error because she attracts a good husband with exactly those qualities that seemed to offend her father. This comes with a natural follow-up argument: Perhaps she needed to be rebellious to be good?
The dramatic irony of time
The buildings of this story are given a special place by the title of the novel. What do the buildings contribute to the plot? They add setting, but also they add a commentary on the dynamic relationship between humans and their environment. The spires point upward, as do many of the religious characters in the book. The tradition that governs them is as old as the buildings and then older still. The irony here is dramatic, because one could say the real plot of the novel in light of the title is that all the humans do their little political dances ignoring the real reference of religion, which is death. After all, that is the first symbol of the book—the death of the beloved bishop. The buildings will survive every character in the plot and their sons and their sons' sons.