In a work of literature, a theme is a recurring, unifying subject or idea, a motif that helps us better understand a work of art. With a novel as richly ambiguous as Catch-22, we look to themes as guides; but it is important to be open-minded and flexible while we do so. A good deal is left to individual interpretation so that one reader might disagree with another without necessarily being "wrong" or "right" about what the novel is saying. Heller employs themes in the manner of a musical composer, often introducing them briefly, then returning as the novel progresses, embellishing and augmenting as he goes. Some of the major themes involve the concept of Catch-22, the distortion of justice, the influence of greed, and the issue of personal integrity.
The code under which the airmen of the 256th Squadron exist is embodied in the theme of Catch-22. As a general rule covering most behavior, it establishes that the men who fight the war are going to have to do what those in authority tell them; and there is no way out of that. Doc Daneeka explains the concept to Yossarian in Chapter 5 when Yossarian asks if his tent mate, Orr, can be grounded. Anyone who is crazy can be grounded. Doc says that Orr certainly could be grounded, but first he would have to make a request. Orr doesn't make that request because he's crazy — he'd have to be crazy to keep flying missions. But if he asked to be grounded, that would mean he is sane. Anyone who wants out of combat duty isn't really crazy and thus cannot get out:
There was only one catch and that was Catch-22, which specified that a concern for one's own safety in the face of dangers that were real and immediate was the process of a rational mind. Orr was crazy and could be grounded. All he had to do was ask; and as soon as he did, he would no longer be crazy and would have to fly more missions. Orr would be crazy to fly more missions and sane if he didn't, but if he was sane he had to fly them. If he flew them he was crazy and didn't have to; but if he didn't want to he was sane and had to.
Yossarian is quite impressed by the simple logic of it all and emits a respectful whistle. "That's some catch, that Catch-22," he observes. Doc Daneeka responds, "It's the best there is."
As a theme, the catch is that anyone under military or political authority has to submit to the will of authority. When Yossarian goes to Rome near the end of the novel and speaks with an old woman, the only one left in the brothel, she tells him that military police and the carabinieri ran the girls out of the apartment building under the authority of Catch-22. Although no one ever actually sees Catch-22, the entire military complex functions under its authority. Why does everyone submit? Because Catch-22 is the law. Who says so? Catch-22, of course.
When Colonel Korn and Colonel Cathcart call Yossarian into their office to discuss the arrangement for his release from military duty (Chapter 40), Yossarian briefly seems to have the commanding officers in a Catch-22. On the one hand, they cannot simply send him home if it looks like a reward for refusing to fly more missions. That would destroy morale. On the other hand, Korn and Cathcart would put their own careers in jeopardy if Yossarian remains with the squadron, refuses to fly, and has other men following his example. In time, of course, Catch-22 prevails on the side of the establishment. Yossarian must either accept the odious deal that he is offered, or he will be court-martialed. It's some catch, that Catch-22.
Justice, or the military distortion of it, is a major theme specifically emphasized in Clevinger's trial (Chapter 8) and the interrogation of Chaplain Tappman (Chapter 36). At cadet school in Santa Ana, California (in 1943), Yossarian's friend Clevinger manages to alienate Lieutenant Scheisskopf by pointing out ways that Scheisskopf could improve morale. For his efforts, Clevinger is brought to trial in front of the Action Board. In a satirical distortion of justice, Heller makes Scheisskopf serve as the prosecutor, the officer defending Clevinger, and a member of the judging panel. Charges stem from the fact that Clevinger tripped one day while marching to class; for this, he is accused of "breaking ranks while in formation, felonious assault, indiscriminate behavior, mopery, high treason, provoking, being a smart guy, listening to classical music, and so on." After a trial that is literally a mockery, in which Heller plays with distorted logic as well as language gone askew, the author reverses the standard concept that a person is innocent until proven guilty: Clevinger is found guilty simply because he is accused. Chaplain Tappman meets a similar fate. Summoned to a cellar without due process or any explanation of charges, the chaplain is interrogated in a harsh and arbitrary manner. Eventually, he learns that he is suspected of signing a hospital letter, which Yossarian forged as a joke, and stealing a plum tomato that Colonel Cathcart actually gave him. His denials are in vain. When he claims that he is not guilty, he is asked, "Then why would we be questioning you if you weren't guilty?" Like Clevinger, Tappman is assumed to be guilty because he is accused. The process is reminiscent of the methods of U. S. Senator Joseph Raymond McCarthy's Senate hearings in the 1950s, which resulted in a national witch-hunt for anyone associated with the Communist Party. Heller quotes a specific McCarthy tactic when one of the accusing officers says to the chaplain, "I have here in my hands now another statement. . . ." McCarthy sometimes would wave a handful of papers and say that he had in his hands the names of so many Communists in some branch of government; but the names would not be released and probably never existed. In the McCarthy hearings, which were front-page news as Heller wrote early drafts of this novel, the presumption of guilt replaced a presumption of innocence. In the novel, that authoritarian approach is taken by the military. (See "Introduction to the Novel" for further discussion of historical context.)
Milo Minderbinder is the most obvious representative of the theme of greed in the novel, but he is not alone; excessive ambition is also a kind of greed, personified by Colonel Cathcart and General Peckem, among others. Milo is a brilliant but corrupt entrepreneur who manipulates his position as mess officer into personal direction of a syndicate (M & M Enterprises) that controls the black market. When Milo's greed gets out of hand, his cash flow is strapped due to a purchase of the entire Egyptian cotton crop. Desperate for funds, Milo contracts with the Germans to bomb his own squadron's base on Pianosa. Heller details the bombing and strafing, during which Milo's pilots spare the landing strip and mess hall so they can land and enjoy a hot meal before retiring. As Milo likes to say, "What's so terrible about that?" For Milo, a contract is a contract; whatever is good for M & M Enterprises is good for the country. But mainly it's good for Milo. Although he claims that everyone has a share in the syndicate, few people see a profit other than Milo. Cathcart and Peckem are greedy for power, which comes with rank and position. Cathcart, the highest-ranked colonel in charge of military operations, keeps raising the number of missions required for an airman to fulfill his tour of duty. He does this to call attention to himself and his ability to get more out of the men, thinking that the ploy will lead to a promotion to general. Peckem already is a general, but he is the director of Special Services — the office dealing with activities and entertainment for the soldiers. Peckem yearns to control military operations. After all, he concludes, what could be more "special" than bombing the hell out of people? Greed leads both Cathcart and Peckem into debilitating corruption. Cathcart is responsible for the deaths of men who have properly served their time and should be going home; one of the survivors, Yossarian, brings humiliation to Cathcart in the end. Peckem finally gets his appointment to military operations — only to find that his own memoranda have resulted in the assignment of the war effort to Special Services. Peckem ends up serving under newly promoted Lieutenant General Scheisskopf, whom Peckem has been walking all over for some time. In this case, greed leads to poetic justice.
The theme of personal integrity runs throughout Catch-22 and is central to an understanding of Yossarian. The novel presents a struggle between individual and institution. Yossarian confronts military authority; but others join him, such as the admirable Chaplain Tappman who changes from a timid soul to a real fighter under Yossarian's influence. In the base hospital, the soldier in white represents loss of identity within the system. No one knows whether the soldier is a man or a woman or black or white or, indeed, whether there is even a soldier inside all that gauze and plaster casing. To regain one's identity, each person must seek his own personal integrity. Yossarian, who would seem most skeptical about integrity, does take a stand in the end. He rejects Colonel Korn's "deal" even though it offers Yossarian an automatic trip home, superficial honor and respect, and peace at last. Although it may seem best for him and for the authorities, Yossarian cannot accept Korn's offer because it would be a betrayal of the rest of the squadron. He would be losing himself to the system. To find himself, he must declare a separate peace and flee.