Science does not know its debt to imagination. Goethe did not believe that a great naturalist could exist without this faculty. He was himself conscious of its help, which made him a prophet among the doctors. From this vision he gave brave hints to the zoölogist, the botanist, and the optician.

Poetry.—The primary use of a fact is low: the secondary use, as it is a figure or illustration of my thought, is the real worth. First, the fact; second, its impression, or what I think of it. Hence Nature was called "a kind of adulterated reason." Seas, forests, metals, diamonds, and fossils interest the eye, but 'tis only with some preparatory or predicting charm. Their value to the intellect appears only when I hear their meaning made plain in the spiritual truth they cover. The mind, penetrated with its sentiment or its thought, projects it outward on whatever it beholds. The lover sees reminders of his mistress in every beautiful object; the saint, an argument for devotion in every natural process; and the facility with which Nature lends itself to the thoughts of man, the aptness with which a river, a flower, a bird, fire, day, or night, can express his fortunes, is as if the world were only a disguised man, and, with a change of form, rendered to him all his experience. We cannot utter a sentence in sprightly conversation without a similitude. Note our incessant use of the word like,—like fire, like a rock, like thunder, like a bee, "like a year without a spring." Conversation is not permitted without tropes; nothing but great weight in things can afford a quite literal speech. It is ever enlivened by inversion and trope. God himself does not speak prose, but communicates with us by hints, omens, inference, and dark resemblances in objects lying all around us.

Nothing so marks a man as imaginative expressions. A figurative statement arrests attention, and is remembered and repeated. How often has a phrase of this kind made a reputation. Pythagoras's Golden Sayings were such, and Socrates's, and Mirabeau's, and Burke's, and Bonaparte's. Genius thus makes the transfer from one part of Nature to a remote part, and betrays the rhymes and echoes that pole makes with pole. Imaginative minds cling to their images, and do not wish them rashly rendered into prose reality, as children resent your showing them that their doll Cinderella is nothing but pine wood and rags: and my young scholar does not wish to know what the leopard, the wolf, or Lucia, signify in Dante's Inferno, but prefers to keep their veils on. Mark the delight of an audience in an image. When some familiar truth or fact appears in a new dress, mounted as on a fine horse, equipped with a grand pair of ballooning wings, we cannot enough testify our surprise and pleasure. It is like the new virtue shown in some unprized old property, as when a boy finds that his pocket-knife will attract steel filings and take up a needle; or when the old horse-block in the yard is found to be a Torso Hercules of the Phidian age. Vivacity of expression may indicate this high gift, even when the thought is of no great scope, as when Michel Angelo, praising the terra cottas, said, "If this earth were to become marble, woe to the antiques!" A happy symbol is a sort of evidence that your thought is just. I had rather have a good symbol of my thought, or a good analogy, than the suffrage of Kant or Plato. If you agree with me, or if Locke or Montesquieu agree, I may yet be wrong; but if the elm-tree thinks the same thing, if running water, if burning coal, if crystals, if alkalies, in their several fashions, say what I say, it must be true. Thus, a good symbol is the best argument, and is a missionary to persuade thousands. The Vedas, the Edda, the Koran, are each remembered by their happiest figure. There is no more welcome gift to men than a new symbol. That satiates, transports, converts them. They assimilate themselves to it,—deal with it in all ways, and it will last a hundred years. Then comes a new genius, and brings another. Thus the Greek mythology called the sea "the tear of Saturn." The return of the soul to God was described as "a flask of water broken in the sea." Saint John gave us the Christian figure of "souls washed in the blood of Christ." The aged Michel Angelo indicates his perpetual study as in boyhood,—"I carry my satchel still." Machiavel described the papacy as "a stone inserted in the body of Italy to keep the wound open." To the Parliament debating how to tax America, Burke exclaimed, "Shear the wolf." Our Kentuckian orator said of his dissent from his companion, "I showed him the back of my hand." And our proverb of the courteous soldier reads: "An iron hand in a velvet glove."

This belief that the higher use of the material world is to furnish us types or pictures to express the thoughts of the mind is carried to its logical extreme by the Hindoos, who, following Buddha, have made it the central doctrine of their religion, that what we call Nature, the external world, has no real existence,—is only phenomenal. Youth, age, property, condition, events, persons,—self, even,—are successive maias (deceptions) through which Vishnu mocks and instructs the soul. I think Hindoo books the best gymnastics for the mind, as showing treatment. All European libraries might almost be read without the swing of this gigantic arm being suspected. But these Orientals deal with worlds and pebbles freely.

For the value of a trope is that the hearer is one; and indeed Nature itself is a vast trope, and all particular natures are tropes. As the bird alights on the bough,—then plunges into the air again, so the thoughts of God pause but for a moment in any form. All thinking is analogizing, and 'tis the use of life to learn metonymy. The endless passing of one element into new forms, the incessant metamorphosis, explains the rank which the imagination holds in our catalogue of mental powers. The imagination is the reader of these forms. The poet accounts all productions and changes of Nature as the nouns of language, uses them representatively, too well pleased with their ulterior to value much their primary meaning. Every new object so seen gives a shock of agreeable surprise. The impressions on the imagination make the great days of life: the book, the landscape, or the personality which did not stay on the surface of the eye or ear, but penetrated to the inward sense, agitates us, and is not forgotten. Walking, working, or talking, the sole question is how many strokes vibrate on this mystic string,—how many diameters are drawn quite through from matter to spirit; for, whenever you enunciate a natural law, you discover that you have enunciated a law of the mind. Chemistry, geology, hydraulics, are secondary science. The atomic theory is only an interior process produced, as geometers say, or the effect of a foregone metaphysical theory. Swedenborg saw gravity to be only an external of the irresistible attractions of affection and faith. Mountains and oceans we think we understand:—yes, so long as they are contented to be such, and are safe with the geologist,—but when they are melted in Promethean alembics, and come out men, and then, melted again, come out words, without any abatement, but with an exaltation of power!—

In poetry we say we require the miracle. The bee flies among the flowers, and gets mint and marjoram, and generates a new product, which is not mint and marjoram, but honey; the chemist mixes hydrogen and oxygen to yield a new product, which is not these, but water; and the poet listens to conversation, and beholds all objects in nature, to give back, not them, but a new and transcendent whole.

Poetry is the perpetual endeavor to express the spirit of the thing, to pass the brute body, and search the life and reason which causes it to exist;—to see that the object is always flowing away, whilst the spirit or necessity which causes it subsists. Its essential mark is that it betrays in every word instant activity of mind, shown in new uses of every fact and image,—in preternatural quickness or perception of relations. All its words are poems. It is a presence of mind that gives a miraculous command of all means of uttering the thought and feeling of the moment. The poet squanders on the hour an amount of life that would more than furnish the seventy years of the man that stands next him.

The term genius, when used with emphasis, implies imagination; use of symbols, figurative speech. A deep insight will always, like Nature, ultimate its thought in a thing. As soon as a man masters a principle, and sees his facts in relation to it, fields, waters, skies, offer to clothe his thoughts in images. Then all men understand him: Parthian, Mede, Chinese, Spaniard, and Indian hear their own tongue. For he can now find symbols of universal significance, which are readily rendered into any dialect; as a painter, a sculptor, a musician, can in their several ways express the same sentiment of anger, or love, or religion.

The thoughts are few; the forms many; the large vocabulary or many-colored coat of the indigent unity. The savans are chatty and vain,—but hold them hard to principle and definition, and they become mute and near-sighted. What is motion? what is beauty? what is matter? what is life? what is force? Push them hard, and they will not be loquacious. They will come to Plato, Proclus, and Swedenborg. The invisible and imponderable is the sole fact. "Why changes not the violet earth into musk?" What is the term of the ever-flowing metamorphosis? I do not know what are the stoppages, but I see that a devouring unity changes all into that which changes not.

The act of imagination is ever attended by pure delight. It infuses a certain volatility and intoxication into all nature. It has a flute which sets the atoms of our frame in a dance. Our indeterminate size is a delicious secret which it reveals to us. The mountains begin to dislimn, and float in the air. In the presence and conversation of a true poet, teeming with images to express his enlarging thought, his person, his form, grows larger to our fascinated eyes. And thus begins that deification which all nations have made of their heroes in every kind,—saints, poets, lawgivers, and warriors.