False Realities
What is real? What is fake? These questions are at the heart of The Man in the High Castle. As a fictional world, the story itself is not real, yet like all novels it takes on its own sense of reality. The question of reality also arises in regard to the well-made fake antiques produced by Frank and sold by Childan: if an item is authentic-looking enough, does it really matter if it lacks the "patina of history"? Even fake objects can have very real effects, as we learn when Tagomi uses his antique pistol to violently defend Baynes.
Artificial Identities
In such an unreal world as that of The Man in the High Castle, how can we really tell that people are who they say they are? Frank has changed his last name and his appearance to hide his Jewish identity, and Baynes claims to have done the same. Baynes presents himself as a Swedish businessman, but over the course of the story he reveals that he is in fact a German spy. And Juliana abruptly discovers that the Italian truck driver Joe Cinnadella is in fact an assassin sent to eliminate the author Hawthorne Abendsen, who is himself not the creative genius he is supposed to be.
Personal Control
Who has control over people’s lives? Childan is anxious about pleasing his Japanese clients, but his client, Tagomi, is worried about pleasing his business contact Baynes. The trajectories of the characters' lives are often out of their control - for example, Frank is arrested for being Jewish by order of Wyndam-Matson, but he is freed when Tagomi absent-mindedly signs a slip of paper calling for his release. Though not all of these characters ever meet each other (e.g., Tagomi and Frank), they still influence each other’s lives.
National Identity
Another element that shapes one's life is one's national identity. Germans are consistently presented as deranged and psychotic, while the Japanese are stern but just. The Americans struggle to express their national heritage while also remaining non-threatening to the Japanese occupiers. How do we maintain our national identity when we have colonized other nations, absorbing their culture and forcing ours upon them?
History
In the novel, history shapes all aspects of our lives, including the jobs people hold and the food they eat. The outcome of a war (an Axis victory rather than an Allied one) has changed the entire face of the earth: Germany is an interplanetary power, America is colonized, Africa has been utterly depopulated, and the Mediterranean has been drained and turned into farmland. Yet at the same time, the significance of history that we give to historical objects (such as FDR's lighter) is constantly called into question.
Prejudice and Colonization
The novel also explores the psychological and social effects of colonization. Items like Civil War recruiting posters have become valuable collectible objects; Japanese occupiers see them as encapsulating true American culture, which has been diluted by (of all things) the Japanese occupation itself. Though this change has created jobs for people like Childan, Frank, and Wyndam-Matson, it has not been positive for everyone. The Southern states, controlled by the German Reich, have reinstituted slavery, and Blacks are relegated to the status of slaves or very low-status workers.
Fascism
Fascism (extreme governmental and social control) best describes the political climate of the German Reich. Complete uniformity is expected, and any challengers to the status quo are quickly disposed of. The novel describes the horrors of fascism and its cost in human lives. This theme also intersects with the themes of reality and authenticity: in a fascist climate, no one can be truly authentic.
