Song Meaning
A simple observation of a rainbow triggers an immediate, profound joy in the speaker. This visceral reaction isn't new; it's a feeling that has accompanied him from the very beginning of his life, persisting through adulthood. The intensity of this feeling is so central to his being that he declares, "So be it when I shall grow old / Or let me die!" This stark choice reveals how essential this pure, unadulterated delight is to his sense of self and his will to live.
The core tension lies in the speaker's desire to maintain this childlike wonder as he ages. He posits that "The Child is father of the Man," suggesting that the formative experiences and emotional responses of youth are the bedrock upon which the adult self is built. The adult man, therefore, should ideally carry forward the uncorrupted spirit of the child, finding the same profound connection to the natural world.
Wordsworth masterfully uses the recurring image of the rainbow as a constant throughout the speaker's life, from infancy to old age. The parallel structure of "So was it when my life began; / So is it now I am a man; / So be it when I shall grow old" emphasizes the enduring nature of this emotional response. The final lines, "And I could wish my days to be / Bound each to each by natural piety," articulate a yearning for continuity, a life woven together by this innate, almost sacred, reverence for nature's simple marvels.