Plath's father was simply human, but the symbol that she creates springs not from a concrete memory of him but from her own mind, and the deepest human understanding of the concept of Father. As a result of personal necessity she breathes life into the innate human concept of the father, a symbol which attains the rank of myth in her work.
The father symbol as portrayed in "The Collosus" is equivalent with the world for Plath. His brow is "weedy acres," and his hair and bones are "littered.to the horizon-line." This father image constitutes the physical elements of existence for the speaker. This aspect of the poem seems representative of the intense importance of the symbol of the father in Plath's psyche.
This image of the colossus is representative of the human concept of God. Plath's recognizes her symbol as life giver, "Nights, I squat in the cornucopia/ Of your left ear, out of the wind." He is that which humans (as represented by the speaker) reside within, and gain protection and sustenance from. .
This interpretation is somewhat contradicted by the lines "Perhaps you consider yourself an oracle,/ Mouthpiece of the dead, or of some god or other." Plath herself alludes to godliness without ascribing the characteristic directly to the colossus. It seems that the figure seems is more earthly than the traditional Judeo-Christian God, closer instead to a pagan symbol. Perhaps the closest parallel would be Zeus, as is suggested by the reference to a "lightning stroke," and the line "O father, all by yourself/ You are pithy and historical as the Roman Forum." .
The colossus is not simply a benevolent giant, he requires tribute from the speaker. She must "dredge the silt from [his] throat," "[scale] little ladders with gluepots and pails of Lysol," and "mend the immense skull-plates." On the personal level this activity suggests Plath's obsession with the father, as well as her overriding dedication to his memory.