In “A Defence of Poetry,” Shelley forces readers to examine their definition of poetry. He claims that poetry is “the expression of the imagination” (5). With this definition, Shelley prompts readers to view poetry as a wellspring that produces everything else, making its importance to society easily recognizable. By encompassing all imaginative works, poetry becomes vital to life.

After broadening the idea of poetry, Shelley goes deeper and distinguishes between his definition of poetry as all works of imagination and the traditional view of poetry: “[P]oetry in a more restricted sense expresses those arrangements of language, and especially metrical language” (10-11). The poetry of Shelley and his contemporaries falls within that narrow definition with arrangements of language and meter. According to Shelley, the classic form of poetry is greater than all other works of imagination because poetry is true imagination. Poetry is the act of taking words, which are not physical, tangible objects, and creating something new. Thus, creating something out of nothing is a higher form of art.

Shelley goes on to say that poetry is not a creation of will; it is a faculty of imagination.