There are many themes in "Long Day's Journey into Night" by America's only Nobel Laureate playwright, Eugene O'Neill. The story deals with a dysfunctional family, all members being addicted to something destructive. James Tyrone, the father, is an alcoholic and a penny-pincher, lost in the glories of his past acting career as the dashing hero in "The Count of Monte Cristo." Mary, the mother, finds escape from the harsh realities of her life through morphine addiction, and she spends much of the play lost in the past, a time when she had hope and innocence and, at least, a future. The older brother, Jamie, is a raging alcoholic, frequents brothels, cannot hold a job, and is jealous of his successful younger brother in a complex love/hate relationship. Edmund, that younger brother (actually the author himself) is, like the other male Tyrones, "in love with the bottle" and very sickly, having recently been diagnosed with TB. He finds escape through reading (especially depressing poetry) and through writing. At least his escapes produced great literature; the escapes of the other three killed them.
Besides escape, there are other themes: blame (each character blames everyone else for all the family members' miseries); cruelty (the characters say awful things and then try, mostly unsuccessfully, to take those statements back); sibling rivalry; drug addiction; alcohol addiction; co-dependency; living in the past; stinginess; love/hate relationships; the Oedipal Complex (Jamie loves his mother deeply and detests his father); and guilt (a strong Irish Catholic guilt) - to name just a few.
Symbolism plays a powerful role in the drama. Fog and the night become areas of escape for Mary, similar to her escape through morphine. She states, "I love the fog. It hides you from the world and the world from you. You feel that everything has changed, and nothing is what it seemed to be. No one can find or touch you any more." (Act Three) In contrast, she hates the foghorn because it cuts through the fog, pulling her back to that ugly word "reality."
Her wedding dress is a symbol of a happy moment in the past but a moment that soon turned tragic. Her dream of "becoming a nun" was destroyed by that marriage, just as her dream of being a concert pianist was destroyed by morphine (HER excuse being the rheumatism in her hands).
Mary can never seem to find her glasses, symbolic of her inability to see the truth, and her husband is constantly turning off lights in the house, symbolic of his stinginess but also of his inability to "see the light."
Another symbol is the creaking floor above stairs. The sound sends shivers through the three Tyrone males because they assume Mary is heading for the "spare room" where she keeps her "stash."
"Long Day's Journey into Night" is, in my opinion, the most powerful American play written. It is thought-provoking, sad, funny, intense, and deeply meaningful all at the same time. Few pieces of literature have ever moved me as much!