Shelley defines imagination as the “mind acting upon those thoughts so as to colour them with its own light, and composing from them, as from elements, other thoughts, each containing within itself the principle of its own integrity” (4). Essentially, this means that imagination acts on thoughts and creates new connections from them. Reason is a tool imagination uses, but imagination is the very fabric of a poet’s tools. Imagination also allows people to see beyond themselves, by putting themselves in another’s shoes

Shelley also describes imagination as bringing delight, as one must go outside of themselves to find delight. Poetry is merely one form of imagination, which allows a reader to be delighted in seeing beauty.

Morality is the distinction between the principles guiding right and wrong. In “A Defence of Poetry,” Shelley argues that poetry is moral because it takes a person out of their worldview and allows them to imagine another reality. Poetry creates empathy by producing kindness, and it discourages bad behaviors by showing the disastrous consequences of evil decisions.

Shelley defines poetry two different ways in “A Defence of Poetry.” Broadly interpreted, poetry is any work of imagination: “Poetry, in a general sense, may be defined to be ‘the expression of the imagination’” (5).