* Reverence for nature: The speaker's joy at seeing a rainbow signifies a profound appreciation for nature's beauty and wonder. This suggests a sense of awe and respect for the natural world, which might be seen as a form of "natural piety."
* Connection to childhood: The speaker's memory of his youthful joy in nature implies a strong link between childhood experiences and a sense of wonder. This connection could be seen as an innate, natural feeling of piety towards the world.
* Sense of wonder: The speaker's heart "leaps up" at the sight of the rainbow, indicating a deep, instinctive emotional response. This suggests that "natural piety" is not merely intellectual but also emotional, rooted in a sense of wonder and awe.
* Ethical implications: Wordsworth's poem also suggests that "natural piety" might have ethical implications. The speaker's hope that he will never lose this feeling of wonder implies a desire to maintain a connection to the natural world and to live in harmony with it.
In short, "natural piety" in "My Heart Leaps Up" likely refers to a deep, instinctive reverence and connection to the natural world, characterized by awe, wonder, and a sense of emotional connection. This feeling is likely rooted in childhood experiences and may have ethical implications, encouraging a sense of responsibility towards the natural world.