Family
Family is an incredibly important component of the play, but family here is not uplifting, supportive, loving, or healthy. Family is corrupt, incestuous, dark, and tangled. It is a burden, a curse, and a heavy stone that pulls one down below the surface of the waves. It is, however, mostly inescapable. Simeon and Peter manage to get out, but Eben is stuck at the farmhouse with his Paw and the spirit of his Maw. He is forever trying to distance himself from his father but finds this difficult; he eventually embraces the vengeful passion of his Maw, but throughout this struggle can barely articulate a self. Family in this play is associated with the land as well; Eben will free himself from his family and from the land with his likely death after the close of the play.
Revenge
The brothers as well as Abbie are obsessed with the idea of revenge, the former three against Cabot and the latter against Cabot and the child she feels comes between her and Eben. Cabot, though, is the primary focus of the characters' ire: he forced them to toil the land until they could find no meaning in it anymore, and worked their mothers to death. He then returns with a young wife who will inherit the farm -an incredible slap in the face to those who gave their lives and their beloved mothers to the farm. The revenge is all consuming, epic in a biblical and Hellenic intensity. It causes the characters to lose self-awareness and perspicacity, leading one to murder an innocent child. Thus, O'Neill's views on revenge are complicated in this play; it may be justified, but can easily become an obsession.
Sex and Desire
Sex and desire fuel Abbie and Eben, but they are not necessarily depicted as immoral impulses. They are purer than the crass greed and materialism that define Cabot and his other sons' lives. It is only the negotiation of those impulses that requires effort. Sex is what brings these unhappy people meaning in their lives, and allows them to subvert their misleading Apollonian strictures. Once Eben and Abbie fully embrace themselves as sexual beings and remove obstacles in their way can they understand the ecstasies of the spiritual.
Religion
Cabot is the most religious character in the play, but his religion is not the warm and fuzzy type. His God is the Puritans' God: harsh, unyielding, and demanding. Cabot comments that God is not "easy" and wants him to continue to demonstrate his work ethic by remaining on the land, toiling away. The other characters do not buy into this version of Christianity. Their religion is passion, sex, money, or revenge; these things, like Cabot’s God, lead them to obsession and despair.
Loneliness
It is a well-known aspect of almost all O'Neill's plays that his characters suffer from profound loneliness, and the characters in Desire are no exception. Cabot speaks openly of how lonely he is, and how no one understands him. He only has his land, and finds more comfort with the cows than other humans. Eben is also lonely, suffering on the farm with brothers who do not understand him, a dead mother, and a returning father whom he hates. Simeon speaks of missing his lover, Jenn. Abbie is profoundly lonely as well, and cannot fathom losing Eben, the one person to offer her "real" love. And finally, we can only guess at the intense loneliness of Cabot's first wives, toiling away on the land that isn't really theirs, dying in obscurity. Human beings are fated to be lonely, O'Neill suggests; this is what religion, modernity, and selfishness bring about.
Work
All of the male characters define their lives by work. Cabot spent his whole life toiling on the farm, and putting his wives to work as well. Simeon and Peter cannot fathom not working for more than ten minutes. Eben also works hard, doing the "chores" the farm necessitates. This is pure Apollonianism, in contrast with Abbie's Dionysianism. Work is backbreaking, cruel, and enervating. Abbie offers Eben something else, and it is Eben's great dilemma to try to resolve this within him.
Nature
Nature and Maw in this play are one and the same. The great elms are described as maternal, brooding, and oppressive. Nature is not necessarily a benevolent force; it is Dionysian, full of passion, vengeful. It tries to subvert the materialism of Cabot, who divides up the land with walls made of hard stone. Nature is not the same as land; Maw may care about the land because she worked it, but she wants Eben free from its cruel clutches.
