The Dinner is an intriguing tale told from a first-person perspective by the unforgettable narrator Paul Lohman, who is about to attend a family dinner with his wife, Claire, along with his brother, Serge, and his wife, Babette. Tensions mount as the dinner between the two families progresses from aperitif to digestif, unraveling the horrifying secrets and leading to a climactic confrontation that forces the characters to confront their values and priorities. The author includes numerous important concepts between the lines, including but not limited to family, morality, and social class, as the characters grapple with questions of right and wrong in the face of difficult choices and challenging circumstances.

The rhetorical question "How far will they go to protect their children” reveals the desire to protect children and family loyalty, intertwining heavily with the actions and motivations of the characters. Serge emphasizes the importance of family loyalty by stating, "Family comes first. Always.” thereby revealing how he expects all family members to prioritize the family and put aside their own desires and needs for the family’s good. Through the statement, “Sometimes family loyalty requires us to do things we don’t want to do, or to keep secrets that we know are wrong,” Paul expresses how they consider family more important than the societal expectation of morally right actions. Paul argues that, “It’s the natural instinct of any parent to want to protect their child, even if it means doing something terrible,” revealing his unwavering determination to protect his son no matter what kind of consequence there will be. The common sentiment between the characters ties them together and concludes keeping the crime a secret. However, the result will be Serge losing his election and a poor, innocent victim dying --- with the murderers free of responsibility since their parents phrase it as an "accident” and they are too young to face the danger and burden of the world. Through the characters' actions, Koch delicately reveals how the characters with the impression of integrity and righteousness have moral compasses that are deeply flawed by prioritizing their personal values instead of societal expectations and how various determinants shape people’s actions. 

The theme of morality is also a central focus of the novel, as the characters grapple with various problems under different circumstances. By claiming that “What’s moral and what isn’t - that’s a subjective matter,” the characters challenge the commonly accepted idea that morality is an objective concept with a universal standard and that individuals' beliefs and personal values indeed shape moral values. Paul points out that “There are situations in life where nothing is black or white, right or wrong,” emphasizing the complexity of morality in reality, demonstrating that it is challenging to discern the “right” solution in many situations. The rhetorical question “What’s more important - your own child, or someone else’s?” highlights the ultimate dilemma between different priorities, underscoring the idea that morality can be a matter of interpretation and perspective, and one’s perception can change when altering the grounds on which they stood. 

Koch also explores social class and race through the restaurant setting. Holding a family dinner at a restaurant where ‘you had to make a reservation months in advance’ establishes the exclusivity of the dining location, thereby revealing the high social status of the characters, and it puts a further emphasis on their power as they have the privilege of not having to reserve a place month prior the dinner. Paul wonders “how many meals for the homeless the cost of one of these dishes could provide,” highlighting the stark contrast between the luxurious meals of the rich and the poverty and homelessness the poor suffer, exacerbating the wealth gap within the country. The lavish lifestyle suggests that the characters are insulated from the harsh realities of life for those less fortunate than themselves. Their wealth and privilege enable them to indulge in luxury and ignore all the hardships people with lower social status suffer. Serge’s adopted son is described as “a child of privilege, adopted into a family of wealth and influence, but he was also a child of color, a visible reminder of the inequalities and injustices that continue to plague our society” reinforces the idea of a complex position in society, as he enjoys some degree of privilege as a member of a family of high social status. Still, at the same time, he also faces discrimination and prejudice because of his race. Though Serge and Babette are trying to convey to the general public their affection towards the adopted son and the equal treatment they receive, the constant repetition of “Michel is our son, and we love him as much as we love our biological son” reinforce the difference between the adopted son and the biological son, therefore suggesting that the adoption was not purely out of love, but as a symbol of generosity to win election votes for Serge. How people perceive adopting a child of color as great kindness highlights the societal bias towards other races and the drastic difference in social class, peeling off the seeming equality that everybody is trying to maintain. 

In conclusion, The Dinner is a thought-provoking novel that explores several common phenomena in the world, delving into the dark underbelly of human nature and exposing our social structures' fragility. This novel is a gripping and unsettling read that will leave readers questioning their own values and assumptions about human behavior within society.