The core human instincts that Freud discussed in his theories, such as instinctual aggression, become common motifs on South Park. Related to the aggression instinct, Freud's theory of the death wish is also present on almost every episode of the show. Until recent years of the production, the character Kenny was killed in every show. The creators of South Park have honed in on the instinctual desire for aggression in the human species, depicting violence in comedic but intense ways. The depiction of violence on South Park would seem to suggest that Freud was correct in his assumption that aggression pervades human nature. Many of the characters on the show throw tantrums, kill each other, and in general express their aggression. The huge following that the show enjoys also illustrates that Freud might not have been far off. Freud's theories are not the only philosophies implicit in the show South Park. Almost without exception, the moral of each episode imparts a tone that resembles Hobbes' and Humes' ideas about human nature, free will, and determinism. For instance, characters are portrayed as being inherently self-seeking, even if they eventually find common ground and cooperate. Thus, Hume's utilitarianism is frequently expressed in South Park episodes. At the same time, a Hobbes-like discourse regarding the need for authority in peaceful societies is also imparted in many of the episodes. Frequently on the show, the town erupts into total chaos and then a few individuals prompt peace based on utilitarian and pragmatic values. Moreover, the conflict between free will and determinism, which Hume and Hobbes examine in detail, is also expressed on the show. For example, the children contend with the fact that they cannot help who their parents are (determinism) and at the same time need to call upon their free will and initiative in order to grapple with tricky social situations.

However much South Park investigates the political impetus toward utilitarianism and pragmatism, many of the episodes reflect the ideas put forth by Danish philosopher Soren Kierkegaard. Commenting...

The social arena of elementary school is a primary illustration of how social alienation begins at an early age. Many of the children, in an attempt to develop a solid identity, become estranged, disenchanted, and isolated. However, South Park also examines broader, macrocosmic manifestations of social alienation: such as when the townspeople come into conflict with powerful political or social institutions that thwart their economic and social well-being. In one episode, the boys challenge their alienation by making their way to Canada on Christmas Eve to protest the Canadian Prime Minister. Many South Park episodes address social structures and social institutions in a critical light, illustrating how individuals and institutions frequently clash. The depiction of social structures and social classes on South Park also hints at Marxist theory. For example, the town of South Park is socially stratified and many families, like Kenny's, are poor.
In spite of its controversial content, South Park offers powerful social commentary and expresses some of our society's core beliefs about human nature. The show imparts a variety of perspectives and philosophies, from Freud to Kierkegaard. Some South Park episodes even include outlandish supernatural situations involving anything from aliens to Satan that challenge the characters to act decisively, to deal with conflict and change. Supernatural situations and mundane situations both serve to underscore our society's beliefs regarding human nature.