There is one central theme to Civilization and Its Discontents: the phenomenon of continued unhappiness that people experience despite the progress of civilization in the ability to satisfy many basic needs. Freud proposes that the main reason for this seeming inconsistency is the tension between an individual's desire for agentic freedom and the increasing demand from society for conformity and the curtailment of desires. Freud argues that the purpose of life is the satisfaction of the pleasure principle and notes that civilization, as a construct created by humans, should also support this end. However, civilization also has to protect the safety of all individuals and support future progress, which requires some level of cultural conformity, as well as the curtailment of some desires which may be injurious to society or to other individuals.

An interesting area that Freud discusses is the issue of technological development, which he concludes is both conducive to happiness and unhappiness. He elaborates on this by noting that family members traveling is a source of unhappiness. In earlier societies, travel was seldom, but when it was undertaken the trips were long and communication was often delayed significantly. As technology developed, it allowed for more rapid communication, which should be conducive to happiness, but also allowed for more frequent travel, which is conducive to unhappiness. Overall, the development of technology is mixed with regard to happiness.

This being a work by Freud, the central drive which is explored is the libido, which is here delineated into the concept of eros (the life drive) and thanatos (the death drive). The curtailment of thanatos is theorized as the purpose behind civilization;s rules and, because this drive cannot be satisfied externally, this curtailment turns the thanatos desire inward, leading to neuroses. Ultimately, civilization supports the development of the super-ego, which creates sensations of guilt for both actual and fantasized transgression of social norms. This guilt is a price that must be paid for the safety and progress or civilization; however, because it is unconscious, it can lead to feelings of discontent among individuals.