The most prominent theme in Whitman’s poem is the divide between scientific knowledge and natural wonder. While the “learn’d astronomer” (Line 1) seeks to understand the stars and bring order to the night sky with his precise measurements and mapping of the stars, the poem’s speaker ultimately longs for a more intuitive, emotional response to the natural world. While the astronomer leans on “the proofs, the figures” (Line 2), and “the charts and diagrams” (Line 3) of his scientific discipline to know the night sky, the speaker is left feeling only “tired and sick” (Line 5) when confronted with so much dry data. The speaker’s decision to go out for a solitary walk allows him to reconnect with the stars in his own way – a way that involves rediscovering the mystery and beauty of nature for its own sake. In describing the “night-air” as “mystical” (Line 7), the speaker emphasizes his own experience as non-formulaic and rooted in a more instinctive and emotional approach. The subtlety of the poem ensures that the poem’s message is not anti-scientific, but rather, pro-wonder. Whitman appears to be gently reminding the reader that nature always remains mysterious and omnipresent, regardless of how much science may advance.