Death
The end of human life is one of the central themes of Louise Gluck's poetry. Her rather dark and sinister writing style lends itself to the discussion of such a terminal fate. However, the discussion of death comes in different shapes. For example, "The Wild Iris" discusses how death feels, what emotions go through the dying through the interpretation of one that is reborn. Another version is found in the death of the caterpillar in "Celestial Music", which is a symbol brushed aside by the narrator of the poem. Both these instances show death as something final and unavoidable. Interestingly, death is not described as something positive either. Reading Louise Gluck's poems one can get the feeling of someone about to die.
Aging
Another big theme in Louise Gluck's poetry is the passage of time through the human life. Aging is not described as something noble but rather as an unavoidable and slow death. This is best exemplified in the poem "Averno", named after the mythological entrance to death, where the lyrical I struggles with memory loss, unable to completely convey her feelings to those generations coming after. Another example can be found in "Vita Nova", where a childhood memory is distorted by time, with all joy taken out of it, as it reminds the narrator of their own aging. As can be seen through these examples, the dark tones of Gluck's poetry are especially prevalent in her discussion of aging.
Religion
Throughout her writing, Louise Gluck often uses imagery from religion and mythology to convey certain feelings. "The Wild Iris", for examples, discusses rebirth, a religious concept. However, the way it is described departs from the wholesome Christian interpretation and takes on a certain mythological character. The narrator of the poem is reborn into a new existence, different from her old one. Another example can be seen in "Celestial Music", which deals with the narrator's atheism. A discussion between two characters is revealed to deal with the narrator's disbelief and inability to see the divine. The gruesome death of a caterpillar is used as a plot device to further the disconnection from the heavens.
Relationship
As expected from Louise Gluck, her poetry only really deals with discord within relationships. A strong example of this can be found in "Horse", where the narrator complains about her husbands emotional distance. Another is the conflict of two friends as mentioned in "Celestial Music". Gluck's take on human interaction is defined by similarly pessimistic assumptions as most of her poetry.