Here are some key themes of this poem:
1. Mortality: The poem begins by establishing the mortal state of Prospero’s father, placing him in the depths of the sea, "full fathom five thy father lies". This conveys the universality of death and the inevitability of the cycle of life and decay.
2. Loss and Grief: Ariel’s song acknowledges and empathizes with the grief of Ferdinand, who believes his father has drowned at sea. The poem underscores the profound sense of loss and anguish experienced by those left behind.
3. Time’s passage: Ariel’s song serves as a reminder of time’s relentless passing and the transience of life. Through imagery such as "of his bones are coral made" and "the sands with dead men’s bones," the poem suggests that even the physical remains of the deceased slowly merge with the elements over time.
4. Nature and transformation: The poem describes how the sea, through its transformative powers, turns the human body into "sea change", resulting in the creation of coral and pearls from the bones. This metaphorical transformation points to the interconnectedness of life, death, and the natural world.
5. Acceptance and remembrance: Despite the sorrowful tone of the poem, there is a sense of acceptance and remembrance implied in the lines "Nothing of him that doth fade,/But doth suffer a sea-change/Into something rich and strange". The transformation, although a sad reality, also suggests a certain beauty and wonder in the enduring legacy left behind.
In essence, the poem "Full fathom five thy father lies" explores the universal and timeless themes of mortality, loss, the passing of time, and the transformative processes that occur after death, leaving readers with a solemn yet lyrical contemplation of life’s ephemeral nature.