As the novel comes the reader receives a briefing of what the main characters of the novel are doing—for instance, Duer now has his own clinic and is a professor, and Joyce tells Latham that if she divorces Martin, she will marry him. Gottlieb is senile. And as for Martin, he is happy at what feels to be the beginning of his real work.
Throughout the novel, Lewis, through his satire, points to the amoral behavior of the medical world at large. The medical profession, for example, has "salesmen" and not "seekers of truth" as its leaders. It is commercial and lacking the precision it should carry. These are just a few examples of what Lewis critiques. Throughout, it is Martin Arrowsmith (along with a few others - like Terry Wickett) that seems to recognize this "amoral" behavior. And yet, in this section, Martin abandons his wife and his child in order to retreat into the woods with his friend to study. It is obvious that, paradoxically, this action of independence is what Martin needed in order to do the kind of research and lead the kind of life he had always been meant to lead. It seems that the fact that he leaves his child and his wife, who he is obviously incompatible with, is not the point of the novel. However, it is something that the reader should take into account and is something that many critics have touched upon because of the irony involved in the action.
Still, the action was, indeed necessary for the novel to end optimistically. Throughout the novel Martin has been an outsider and it is not until these final chapters that Martin comes to terms with that status. He becomes aware, when Joyce wants him to take on the directorship and abandon his research, that she does not truly understand the importance of his work. This is not to say that he had not fallen into the temptation of Joyce and her world of riches. He, in fact, actually learns golf and somewhat comes to enjoy the luxuries that she gives him. It even takes him a while to become accustomed to Terry's lifestyle when Martin finally decides to join him. But Martin, is happiest at Birdie's Nest - it is there that he finally has the freedom, not only to be himself, but also to do the kind of research that he and Terry feel is important. They no longer have to be pressured into publication and they no longer have to study "influenza," if they do not want to, simply to appease the heads and to "keep- up" with one institute or another.
The character of Terry Wickett is important in this section because he has the courage to do what Martin could not do at first—he resigns from McGurk when he has had enough. Granted, Wickett is not faced with the responsibility of a family, but that had been his choice. Moreover, it is as if, without Wickett's lead, Martin could not have made the step he made into freedom. Martin is not an all-together self-assured character and it is not until the very end that he achieves the "sureness" Gottlieb had once shown.
Martin has had to lose his wife and mentor in order to achieve his destiny. It is, however, a lonely and difficult destiny, which Lewis points to over and over again and illustrates through Wickett and Gottlieb. An entire dissertation may be written, moreover, on the "romanticism" involved in the creation of a character like Martin Arrowsmith.