French Revolution destroyed the old order and social situation, which also leaded in the changes of people’s minds in different classes. After French Revolution, people tend to advocate “liberty, equality, and fraternity”. In this way, French Revolution actually drives Romanticism and the spirit of French Revolution becomes the foundation of Romanticism.

According to “A Defense of Poetry”, Shelley defined poetry as “the record of the best and happiest moments of the happiest and best minds”. Human beings in the society are all emotional creatures, and poetry allows people to express feeling with language. In addition, Shelley thought that “poetry redeems from decay the visitations of the divinity in man”. It also shows that poetry can help people to express themselves. As for poets, Shelley considered them as “the hierophants of an unapprehended inspiration”, because in poetry, there are combinations of a large amount of unapprehended thought. The reason that poetry can bring civilization to the society is poets are able to shift people’s mind into language. However, poets are not only the authors, but also “the unacknowledged legislators of the world”, because Shelley believes poets have the mortal power, who have ability to tell right and wrong. In other words, poets have to be reasonable.

Romanticism focused on the absolute freedom of creating and expressing. It means the content of poetry should be uncontrollable. Romantics requested to stop those outmoded rules and taboos of Classicism. For Shelley, poetry, which is like a mirror, has ability to reveal both of the beautiful side and the hidden ugly side of the world. This is the most important function of poetry. People are not only supposed to accept the society, but also to deal with the social problems. And poetry is a way to awaken people and let people know what is right and what is wrong.

All in all, during the period of Enlightenment and French Revolution, people focused on reason and civil rights, in contrast, Romanticism emphasized the significance of emotion, feeling and imagination. In other words, Romanticism is introspection for Enlightenment and French Revolution.