The nature of love
The nature of love is one of the most significant themes in Foe. At the start of the novel, readers are introduced to Junior and Henrietta, who live a quiet and isolated life on a farm in the middle of nowhere. One day, a man named Terrance comes to visit them and tells them that Junior will be forced to be away for three years and work at an installation in space. The young couple, who is deeply in love and appears to have few problems in their relationship, are deeply upset by this revelation and wonder how they will cope—especially Henrietta, who will be completely alone on the farm. To ease the fear, Terrance tells the couple that he will provide Henrietta with an android that copies Junior's appearance and personality almost exactly. As Terrance spends more time around the couple, ostensibly gathering information on Junior so that he can create the best android possible, their relationship starts to fracture, and their love starts to change. Although they still love each other deeply, the possibility of an android being introduced into Henrietta's life causes Junior to become jealous. Their love becomes conditional on Junior returning and their love returning to what it once was.
The revelation at the end of the novel—that the Junior readers had come to know is the android, not the human version of Junior—reveals that their love remained strong while Junior was away. However, the nature of their love slightly changed because of the time they spent apart.
The increasingly blurry line between humans and androids
Throughout much of Foe, the line between humans and androids becomes increasingly blurred. In the present day, people are relatively easily able to tell the difference between humans and androids. In the world of Foe, however, only eagle-eyed readers are able to discern that the Junior readers come to know throughout the novel is an android, not the human he claims to be. In fact, the android version of Junior believes that he is a human. After all, he has many of Junior's memories, acts like him, and looks like him. They are nearly identical, proving the power of technology and the ingenuity of human beings, who researched and rapidly improved their technology.
