Frazier leads the group to the roof to watch the sunset with other members of the community. In a discussion with Castle, he lists what he thinks are the essentials of the Good Life: health, a minimum of unpleasant labor, the chance to develop talents and abilities, satisfying personal contacts, and relaxation and rest. These are the foundational goals that Walden Two takes for granted. Concretely, they are implemented by the Walden Code, which specifies how people are to interact with each other. The rules that make up the Code range from the trivial to the serious, including such trivialities as "Don't talk to outsiders about the community" and "Never say thank you.'"
Castle tells Frazier that he thinks that exceptional men and women would not be challenged to excel in the Walden Two community. Frazier replies that the traditional means of motivation--competition, personal fame or wealth--are not in operation, but that people are nonetheless motivated to achieve. Castle argues that Walden Two may have achieved the Good Life, but it is not valid without a moral law to support it. Frazier replies that the Good Life is the Good Life, however achieved. Burris steps in to ask about the experimental method that is the backbone of Walden Two's practices: aren't they lacking in good controls? Frazier replies that the criticism is valid, but when the connections between cause and effect are as clear as they are at Walden Two, no controls are necessary.
After this discussion, Burris heads to the gardens to have a smoke. He notes to himself that his interest in cigarettes seems to wane with each day he spends at Walden Two. Steve and Mary, who have been told by Castle that Burris was in the gardens, catch up with him and ask him his opinion of Walden Two. They are thinking of joining. Burris says that everything seems to be in good order; it would be a great place for them to settle. They decide to stay, and thank Burris for his advice. Burris feels jealous of Frazier for having built a community that young people such as Steve and Mary are so excited to join. He begins to wonder if he, too, could live at Walden Two.
The next morning, Castle informs Burris that he thinks the whole thing is a hoax. Walden Two is a success not because of the principles of which Frazer has been telling them but because of Frazier's "personal magnetism." When Burris challenges his assessment, Castle admits that the idea is silly, but he can't help but feel that there is something going on behind the scenes.
At breakfast, Steve and Mary tell the group that they have been interviewed for membership in Walden Two but will have to wait until the afternoon to know if they have been accepted. Rodge and Barbara argue quietly; it is clear that Barbara is not as enthusiastic about Steve and Mary's decision as Rodge is. After breakfast, the group finishes washing the windows of the Walk. Around noon they take a tour of the medical facility, where Mr. Meyerson, Mrs. Meyerson's husband, tells them that doctors at Walden Two have many privileges compared to doctors in the outside world. They can ask for personal checkups at any time and they can implement large-scale preventative measures, such as changes in the food served in the dining rooms or in sanitation practices, when necessary.
Chapter 20 is one of several long chapters, scattered throughout the novel, in which Frazier and Castle battle over the basic tenets of Walden Two. Here, the focus is on defining and achieving the Good Life. As always, Frazier is the radical empiricist: he argues that whatever produces good results is the right thing to do. Castle sticks to the idea that freedom and moral law are good in and of themselves. It has become clear by now that the differences between Castle and Frazier are unresolvable. They have different basic assumptions about what is worthwhile. From here on in, they will simply re-hash much of the same material, Frazier maintaining the positions he has always held and Castle becoming increasingly adamant in his opposition.
Burris remains the neutral observer throughout the chapter. Only at the end does he chime in with a question of his own. Unlike Castle, he focuses on Frazier's claim that the design of Walden Two is scientific. An experimental "control" is a way of ensuring that the results of a manipulation are caused by that manipulation and not by some other factor. For instance, if a researcher wanted to show that a particular drug was an effective treatment for the common cold, it would be important to include both an experimental group of patients who received the drug and a control group who did not receive the drug. Otherwise, any improvement in patients who took the drug could be attributed to other factors: natural recovery, weather changes, and so on. Frazier argues that although yes, it is impossible to effectively control for many of the variables of interest at Walden Two, it is unnecessary to do so. The connection between cause and effect is obvious: self-control leads to happiness.
There is a grain of truth in what Frazier is saying, but also a large amount of evasion. Walden Two is in principle based on a science of behavior, but here, as anywhere, the practical and ethical problems of performing well-controlled studies on humans are nearly insurmountable.
Burris's fading desire to smoke, illustrated in Chapter 21, is a sign that things really are different at Walden Two. Even life-long habits can disappear in the right environment. Burris analyzes his decreased desire to smoke in terms of which Frazier would have approved: at first, he stopped smoking because of perceived social pressure; after a while, he lost the desire itself. Presumably, this is what is supposed to happen in all spheres of life when an adult from the outside world becomes a member of Walden Two.
Chapter 22 wraps up some loose ends. The two couples, Steve and Mary, and Rodge and Barbara, have clearly diverged. At the beginning of the novel there was little to differentiate them, but after a few days at Walden Two it is clear that Steve and Mary are the prototypical new members of Walden Two, while Rodge and Barbara are the prototypical couple that is unwilling to abandon the outside world.