"The child is father to the man," what does this quote actually mean?
This quote comes from a poem called "My Heart Leaps Up" and articulates a theme that threads it way throughout Wordsworth's poems. It's a theme that is also dear to Romanticism in general: the idea that the child has a natural purity, or as the poem says, a "natural piety," that is gradually eroded and corrupted by contact with the civilized world. The world jades us, rubbing away our sense of wonder. The idea, also expressed by Wordsworth in the statement that the child is born trailing clouds of glory, is that the younger you are, the closer you are to that godhead or divine source from which we all spring. In "My Heart Leaps Up," the poet notes that his heart leaps up when he sees a rainbow, just as it would when he was child seeing a rainbow. He wants very much to keep that sense of wonder at a rainbow until he "shall grow old." If his heart ever stops leaping up in childlike joy at nature's beauties (symbolized by the rainbow), he says, "let me die!" It is only as he is informed by childlike joy and wonder that life is worth living. This short poem never says that civilization corrupts people, but it strongly implies that the child's innocent wonder is more valuable than an adult sophistication that would not allow a heart to leap in joy at a rainbow.