Extracts from A Defence of Poetry by Percy Bysshe Shelley
Poets, according to the circumstances of the age and nation in which they appeared, were called, in the earlier epochs of the world, legislators, or prophets: a poet essentially comprises and unites both these characters. For he not only beholds intensely the present as it is, and discovers those laws according to which present things ought to be ordered, but he beholds the future in the present, and his thoughts are the germs of the flower and the fruit of latest time. … 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.
ref: politics
The distinction between philosophers and poets has been anticipated. Plato was essentially a poet—the truth and splendour of his imagery, and the melody of his language, are the most intense that it is possible to conceive. He rejected the measure of the epic, dramatic, and lyrical forms, because he sought to kindle a harmony in thoughts divested of shape and action, and he forbore to invent any regular plan of rhythm which would include, under determinate forms, the varied pauses of his style. Cicero sought to imitate the cadence of his periods, but with little success. Lord Bacon was a poet. (Footnote: See the Filum Labyrinthi, and the Essay on Death particularly). His language has a sweet and majestic rhythm, which satisfies the sense, no less than the almost superhuman wisdom of his philosophy satisfies the intellect; it is a strain which distends, and then bursts the circumference of the reader’s mind, and pours itself forth together with it into the universal element with which it has perpetual sympathy. All the authors of revolutions in opinion are not only necessarily poets as they are inventors, nor even as their words unveil the permanent analogy of things by images which participate in the life of truth; but as their periods are harmonious and rhythmical, and contain in themselves the elements of verse; being the echo of the eternal music. Nor are those supreme poets, who have employed traditional forms of rhythm on account of the form and action of their subjects, less capable of perceiving and teaching the truth of things, than those who have omitted that form. Shakespeare, Dante, and Milton (to confine ourselves to modern writers) are philosophers of the very loftiest power.
ref: philosophical method
The great secret of morals is love; or a going out of our own nature, and an identification of ourselves with the beautiful which exists in thought, action, or person, not our own. A man, to be greatly good, must imagine intensely and comprehensively; he must put himself in the place of another and of many others; the pains and pleasures of his species must become his own. The great instrument of moral good is the imagination; and poetry administers to the effect by acting upon the cause. … But I digress.—The connexion of scenic exhibitions with the improvement or corruption of the manners of men, has been universally recognized: in other words, the presence or absence of poetry in its most perfect and universal form, has been found to be connected with good and evil in conduct or habit.
ref: moral epistemology
And Milton’s poem contains within itself a philosophical refutation of that system, of which by a strange and natural antithesis, it has been a chief popular support. Nothing can exceed the energy and magnificence of the character of Satan as expressed in Paradise Lost. It is a mistake to suppose that he could ever have been intended for the popular personification of evil. Implacable hate, patient cunning, and a sleepless refinement of device to inflict the extremest anguish on an enemy, these things are evil; and, although venial in a slave are not to be forgiven in a tyrant; although redeemed by much that ennobles his defeat in one subdued, are marked by all that dishonours his conquest in the victor. Milton’s Devil as a moral being is as far superior to his God, as one who perseveres in some purpose which he has conceived to be excellent in spite of adversity and torture, is to one who in the cold security of undoubted triumph inflicts the most horrible revenge upon his enemy, not from any mistaken notion of inducing him to repent of a perseverance in enmity, but with the alleged design of exasperating him to deserve new torments. Milton has so far violated the popular creed (if this shall be judged to be a violation) as to have alleged no superiority of moral virtue to his God over his Devil. And this bold neglect of a direct moral purpose is the most decisive proof of the supremacy of Milton’s genius. He mingled as it were the elements of human nature as colours upon a single pallet, and arranged them in the composition of his great picture according to the laws of epic truth; that is, according to the laws of that principle by which a series of actions of the external universe and of intelligent and ethical beings is calculated to excite the sympathy of succeeding generations of mankind.