Walt Whitman's 1867 poem "When I Heard the Learn'd Astronomer" finds the speaker in a lecture room with the astronomer talking about the stars and showing off "charts and diagrams." In the first half of this short poem (a single stanza of eight lines), the speaker passively absorbs the information. The turn comes in line 5 when he becomes "tired and sick."

Whitman's thematic concerns in the poem are twofold. He is pointing out how science wants to quantify, analyze, and intellectualize everything it looks it, in this case the universe. Whitman was writing at a time when science was making great advances, and the world was becoming better understood. Darwin's On the Origin of the Species, for example, was published in 1859.

While the astronomer may be "learn'd," it is clear that this adjective is mainly ironic. For Whitman, science can remove the poetry and wonder from nature, really, it removes everything that makes nature natural. Nature has always been a great theme for poets, and Whitman contrasts the poet's approach with the scientist's approach. Rather than lecture about the stars or graph the their positions, the stars should simply be enjoyed and experienced. This is what the speaker does in the final line.

It also seems significant that speaker is alone at the end of the poem. Whitman, in a very Romantic way, seems to be saying the nature is best appreciated in solitude. This stands in contrast to the crowded lecture hall where someone is speaking, and the audience is applauding. For Whitman, the stars need to be seen alone and in silence, not through a scientific lens in a building.