The life and works of Percy Bysshe Shelley exemplify English Romanticism in both its extremes of joyous ecstasy and brooding despair. Romanticism’s major themes—restlessness and brooding, rebellion against authority, interchange with nature, the power of the visionary imagination and of poetry, the pursuit of ideal love, and the untamed spirit ever in search of freedom—all of these Shelley exemplified in the way he lived his life and live on in the substantial body of work

Shelley's poetry reflects his deep-rooted rebellion against social and political oppression. In works such as The Masque of Anarchy and Ode to the West Wind, he fiercely criticises oppressive institutions, calling for justice, equality, and the liberation of the human spirit

While the doggerel verse does not foreshadow Shelley’s mastery of the lyric, the subject matter of the poems is characteristically Shelleyan: poetry, love, sorrow, hope, nature, and politics.

In Shelley’s poetry, the figure of the poet (and, to some extent, the figure of Shelley himself) is not simply a talented entertainer or even a perceptive moralist but a grand, tragic, prophetic hero. The poet has a deep, mystic appreciation for nature, and this intense connection with the natural world gives him access to profound cosmic truths,

Shelley demonstrates a great reverence for the beauty of nature, and he feels closely connected to nature’s power. In his early poetry, Shelley shares the romantic interest in pantheism—the belief that God, or a divine, unifying spirit, runs through everything in the universe. He refers to this unifying natural force in many poems, describing it as the “spirit of beauty”

This force is the cause of all human joy, faith, goodness, and pleasure, and it is also the source of poetic inspiration and divine truth. Shelley asserts several times that this force can influence people to change the world for the better.

Shelley simultaneously recognizes that nature’s power is not wholly positive. Nature destroys as often as it inspires or creates, and it destroys cruelly and indiscriminately. For this reason, Shelley’s delight in nature is mitigated by an awareness of its dark side.

Shelley uses nature as his primary source of poetic inspiration. In such poems as “The Mask of Anarchy Written on the Occasion of the Massacre at Manchester” (1819) and “Ode to the West Wind,” Shelley suggests that the natural world holds a sublime power over his imagination. This power seems to come from a stranger, more mystical place than simply his appreciation for nature’s beauty or grandeur. At the same time, although nature has creative power over Shelley because it provides inspiration, he feels that his imagination has creative power over nature.