The letters that Moses writes to "newspapers, to people in public life, to friends and relatives and at last to the dead" appear in almost every chapter in the novel. These letters illustrate Moses' attempt to put the world around him in some kind of order. He talks and talks and writes and writes, trying to iron out the contradictions that exist in his philosophy, his life, and the life of others. The technique seems to work: by the end of the novel, he can stay peacefully silent. Moses has nothing else to say for the moment, "not a single word." He has not actually created organization or stability through his letter writing, but the process has, more importantly, allowed him to come to an understanding of himself and see that stability is not a goal in the first place.
Philosophy and psychology are present throughout the novel. Moses constantly makes references to philosophies of his own, of the ancients and moderns, and of new scholars. Philosophy becomes a kind of religion for Moses, and he tries to tear it apart in order to understand it. In the end, he finds that his personal philosophy is a mixture of philosophies, and he need not decide on any one philosophy in order to be satisfied.
Moses has seen a psychiatrist, and he references ideas of psychology. Psychology serves mostly as an object of satire in the novel; both Bellow and Moses find humor at its expense.
Women are both the cause of and the antidote to Moses' suffering. His wives pain him, his casual loves give him diseases. Some women represent Moses' tendency to rely on sex for comfort. He also seeks stability in marriage. Over the course of his relationship with Ramona, Moses begins relating to women in a new way. He stops thinking of marriage as an easy solution to his problems, and of sex as the cure for what ails him.