'A Defence of Poetry' is an essay written by the Romantic poet Percy Bysshe Shelley (1792-1822). One of the most important prose works of the Romantic era, and a valuable document concerning Shelley's own poetic approach, the essay is deserving of closer analysis and engagement.

You can read Shelley's 'A Defence of Poetry' here before proceeding to our summary and analysis of the essay below.

'A Defence of Poetry': summary

Shelley wrote 'A Defence of Poetry' in 1821 in response to an essay written by his friend, Thomas Love Peacock. In 'The Four Ages of Poetry', Peacock – now best-remembered for novels like Nightmare Abbey – wittily argued that poetry was surplus to requirements in the modern age, because scientific and technological discoveries had rendered it unnecessary. We can get all the wonder we need from science. Arguing from a Utilitarian position, Peacock (with his tongue if not firmly in his cheek then certainly languidly resting against it) suggests that poetry is of less use to modern man than it was in previous ages.

Shelley intended his essay to be published in the follow-up issue of the Literary Miscellany, which had published Peacock's essay that had prompted Shelley's rebuttal. However, the Miscellany folded after its first issue, so Shelley's essay was never printed – and it only appeared in print in 1840, eighteen years after Shelley's death, when his widow, Mary Shelley, published it.

Shelley argues that poetry is mimetic: that is, it reflects the real world. In the early days of civilisation, men 'imitate[d] natural objects', observing the order and rhythm of these things, and from this impulse was poetry born. Reason and imagination are both important faculties in the poet. Reason, he tells us, is logical thought, whereas imagination is perceiving things, and noticing the similarities between things (here, we might think of the poet's stock-in-trade, the metaphor and simile, which liken one thing to another). It is through reason but also through imagination that we can identify beauty in the world, and from such a perception or realisation are great civilisations made. Poets, then, are the makers of civilisation itself, as Shelley argues:

But poets, or those who imagine and express this indestructible order, are not only the authors of language and of music, of the dance, and architecture, and statuary, and painting: they are the institutors of laws, and the founders of civil society, and the inventors of the arts of life, and the teachers, who draw into a certain propinquity with the beautiful and the true that partial apprehension of the agencies of the invisible world which is called religion.

The poet throughout history has been both legislator (law-maker) and prophet (religious messenger). And because poets work within the medium of language (unlike the sculptor or painter, who works in the visual medium), they have attained a greater degree of fame than other artists.

Shelley distinguishes between 'measured' and 'unmeasured' language, the former being poetry (which uses metre, i.e., you measure out the syllables per line) and the latter being prose. Poetry is superior to prose, even though both use language, because poetry also taps into the possibilities of sounds: 'the language of poets has ever affected a certain uniform and harmonious recurrence of sound, without which it were not poetry, and which is scarcely less indispensable to the communication of its influence, than the words themselves, without reference to that peculiar order.'

Shelley also makes a distinction between storytelling (and, indeed, history) and poetry, arguing, 'A story of particular facts is as a mirror which obscures and distorts that which should be beautiful; poetry is a mirror which makes beautiful that which is distorted.' Poetry thus reflects the world, like a mirror, but does so in a way that renders the distorted image beautiful.

Indeed, poetry can make us see the world in a new light, making it richer and more beautiful:

Poetry lifts the veil from the hidden beauty of the world, and makes familiar objects be as if they were not familiar; it reproduces all that it represents, and the impersonations clothed in its Elysian light stand thenceforward in the minds of those who have once contemplated them, as memorials of that gentle and exalted content which extends itself over all thoughts and actions with which it coexists.

The key to all of this, Shelley reiterates, is imagination.

Shelley devotes the next portion of 'A Defence of Poetry' to a sort of critical history of poetry from the days of ancient Greece up to the present, considering how, throughout the ages, poets have had a moral influence upon the world. He argues that, following the Fall of Rome and the establishment of Christianity, it was poets who saved the world from ruin and anarchy: 'the world would have fallen into utter anarchy and darkness, but that there were found poets among the authors of the Christian and chivalric systems of manners and religion, who created forms of opinion and action never before conceived; which, copied into the imaginations of men, became as generals to the bewildered armies of their thoughts.'

He sees the medieval poet Dante (1265-1321) as the 'bridge' between the ancient and modern world. Responding to Peacock, Shelley argues that the poet's purpose is utilitarian, since poetry 'lifts the veil from the hidden beauty of the world', and has a moral purpose. Shelley concludes his essay with the rousing and famous words:

Poets are the hierophants of an unapprehended inspiration; the mirrors of the gigantic shadows which futurity casts upon the present; the words which express what they understand not; the trumpets which sing to battle, and feel not what they inspire; the influence which is moved not, but moves. Poets are the unacknowledged legislators of the world.

'A Defence of Poetry': analysis

Shelley's was not the first great defence of poetry as an art form, and probably the most notable precursor in English literature is Sir Philip Sidney's 'An Apology for Poetry', from the 1580s. But Shelley's argument is more closely keyed into his own time, and emphasises some key aspects of Romanticism as a literary movement, and the importance of the poet as a figure in that movement.

Shelley's central argument in 'A Defence of Poetry' is, at bottom, a moral one: poets enhance our sympathetic imaginations and thus poetry is a force for moral good. This is why, in that often-quoted final line, 'poets are the unacknowledged legislators of the world': because poets have both the moral purpose and the imaginative faculties which help to make our world and its moral systems what they are.

As M. H. Abrams observed in his analysis of 'A Defence of Poetry', in his brilliant The Mirror and the Lamp: Romantic Theory and the Critical Tradition (Galaxy Books), Shelley's argument in 'A Defence of Poetry' is in some ways a Platonic one, concerned with 'eternal Forms'; but crucially, whereas Plato had written of poets as the rivals of philosophers and statesmen as imitators of the natural world, Shelley collapses this rivalry and argues that great lawmakers and philosophers are poets.

Critics have often noticed that 'A Defence of Poetry' is a great essay on poetry in spite of what it leaves out: there is no detailed history of the development of poetry (Shelley's whistle-stop tour of classical and medieval poets notwithstanding), nor is there any list of rules which good poets should follow. Instead, Shelley's argument is one which reflects many of the tenets of the Romantic movement: the idea of the poet as a visionary or prophet, the primacy of the imagination, and the ways in which the poet can change the world, becoming lawmaker, statesman, and philosopher all in one.