Summary and Analysis: Calamus
When I Heard the Learn'd Astronomer""
The scholarly astronomer lectured with the aid of figures, charts, diagrams, and tables. Soon the poet felt tired and so he escaped from the lecture room and went outside, where he breathed "the mystical moist night-air" and "look'd up in perfect silence at the stars."
Whitman is saying that the true way to understand nature is not scientific but intuitive and mystical. The poet can feel and understand the processes of nature when he is experiencing them, but listening to people lecture about them merely makes him "tired and sick."