Identity
Events in the novel constantly undermine Walter's sense of his identity. In this sense, Homo Faber can be seen as Walter's necessary journey towards "making" or "re-making" his own self. Walter's sense of his identity is bound closely with his profession as Technologist. He believes that being a technologist influences the way he sees the world. But as the events around him undermine his faith in technology, Walter begins to see that he cannot base his identity on what he does in the world. This transformation is completed when Walter gives Williams his notice. He no longer needs his job to define his identity.
The need to redefine himself goes deeper, too: Walter begins to doubt that he has any coherent self when he realizes how little anyone around him knows who he is. The crisis in this development occurs when Walter leaves Williams's party. When he reaches someone living in Walter's own apartment who does not know who "Walter Faber" is, Walter realizes how few connections he has made in his life. In returning to Greece and to Hanna, Walter implies that Hanna is the only one who really knows him. She knows about Sabeth, and she knows about Walter's mistakes. In some ways Walter at the end of the novel has less of a social identity than he did at the beginning, although he has a clearer sense of the identity he has made for himself in his life. He has no job, no apartment, no girlfriend, no colleagues. But he has Hanna. He knows he will not die alone, and he knows that someone will remember him if he does die. For Walter, that is enough.
Guilt and Innocence
Walter is obsessed with the ideas of guilt and innocence. He sees actions as crimes and consequences as punishments. These concepts help Walter avoid the idea of fate. If Walter did not choose his actions, he hardly could be declared guilty for them. At the same time, perhaps Walter is tempted to accept fate because he fears being judged guilty for Sabeth's death.
At the beginning of the novel, Walter's concepts are clear and simple. Only one party can be guilty at a time; if Hanna guiltily prevented them from getting married, then Walter is innocent. If Sabeth came to his room in Avignon, she is guilty but Walter is not. By the end of the novel, Walter has developed a more complex understanding. It is possible for everyone to be guilty of something, and innocence does not protect a person from the consequences of his actions.
Ultimately Walter is freed from this obsession with guilt, not because he stops believing in guilt but because he begins to understand the concept of forgiveness.
Technological Omnipotence
"Technological omnipotence" describes the belief that everything is possible and that technology will allow human beings to control every aspect of their lives. This view is constantly contradicted by the events of the novel, yet Walter's consistency reminds the reader that despite the implausibility of this view, it is also extremely attractive. While technology might not be the panacea that Walter once thought it to be, the idea of technological omnipotence will constantly reassert itself in opposition to a sense of powerlessness.
Frisch may well have had the nuclear bomb in mind in his vision of technology and its powers and limits. The idea of the bomb is incredibly appealing in that it may be the best tool for national security. But the bomb, just like technology in general, creates its own new problems, and it cannot solve problems that are rooted in human misunderstanding. Forging real human connections may well be more powerful than any technology.
Coincidence versus Fate
The events in Homo Faber can be seen in two ways. Either a string of coincidences resulted in an extremely unlikely (yet real) outcome; or a group of people carried out their destiny, and they could not have made different choices. This dichotomy in perspective encompasses a larger series of seeming antinomies: faith or reason, modern knowledge or ancient beliefs, free will or predestination? Walter never seems to resolve this particular conflict. This irresolution suggests that Frisch is more concerned with exploring these two ideas than presenting one as simply correct. Both ideas seem to work in understanding why things happen in the narrative as they do.
Death
Death is a common trope in the novel--from the zopilotes that seem to dog Walter's footprints, to multiple violent deaths, to everyday objects that take on morbid aspects (Hanna's bathtub as a coffin, for example). Walter's fear of death both creates and responds to such images. One way of understanding death in the novel is to consider the fact that human beings have always feared death, so as Walter begins to accept his fear, he also begins to more easily see the imporance of making connections with others before it is too late. The idea of death also helps remind readers of the historical context of the novel and the theme of war. The constant presence of death lingers even though the war has ended, for in the novel at least, war continues to create violence and death long after it has been declared to be finished.
Art
Walter's inability to appreciate art suggests that he sees value only in the useful or practical. As a novelist and a playwright, Frisch inherently makes an argument for the importance of art; yet, in Homo Faber, Frisch is focused on art's importance for the audience, rather than on its creator. One of the questions posed in the novel is whether or not art is an inherent human trait. Is Hanna right? Does everyone have an instinctive reaction to art? If so, Walter's dislike of art may stem from the same kind of fear that undermines his sense of his identity. Walter pulled away from art because he feared the uncontrollable sense of connection that arose from being moved by a piece of art. Only after Sabeth's death does Walter know what it is like to share such moments of mutual understanding and pleasure (and then to lose them forever). Only then is Walter able to appreciate the fleeting yet universal experience of responding to art.
Travel
Walter constantly is on the move. He visits multiple continents, almost a dozen countries, and dozens of cities. He uses a wide variety of modes of transporation--from trains to planes to donkeys. He travels for pleasure and for business. In general, travel is one of the major components of the novel's dislocation of Walter, who has no real home, no real country. The ease with which he moves about the world only enhances Walter's ability to avoid permanent connections, to escape responsibilities, and to remain completely unknown and un-judged. In this sense he is a nomadic refugee of sorts.
The abundance of travel in the novel suggests another limitation of technological omnipotence. One might have argued that moving around and being exposed to different cultures would increase Walter's connections with different people and different countries. (This is an important founding idea of UNESCO: the international exchange of technologies will lead to greater understanding.) Instead, Walter's constant motion has the opposite effect; seeing cultural difference helps him understand his own identity. One must come to appreciate what is universal in human technology and culture in order to form the most solid human bonds; mere tolerance of difference is a poor substitute.
