As there are certain sounds that excite certain movements, and the song and dance go together, so there are, no doubt, certain thoughts that lead to certain tones of voice, or modulations of sound, and change "the words of Mercury into the songs of Apollo." ... The jerks, the breaks, the inequalities and harshnesses of prose are fatal to the flow of a poetical imagination, as a jolting road or a stumbling horse disturbs the reverie of an absent man. But poetry "makes these odds all even." It is the music of language, answering to the music of the mind, untying, as it were, "the secret soul of harmony." Wherever any object takes such a hold of the mind as to make us dwell upon it, and brood over it, melting the heart in tenderness, or kindling it to a sentiment of enthusiasm; wherever a movement of imagination or passion is impressed on the mind, by which it seeks to prolong and repeat the emotion, to bring all other objects into accord with it, and to give the same movement of harmony, sustained and continuous, or gradually varied, according to the occasion, to the sounds that express it--this is poetry. The musical in sound is the sustained and continuous; the musical in thought is the sustained and continuous also. There is a near connection between music and deep-rooted passion. Mad people sing. As often as articulation passes naturally into intonation, there poetry begins.... It is to supply the inherent defect of harmony in the customary mechanism of language, to make the sound an echo to the sense, when the sense becomes a sort of echo to itself--to mingle the tide of verse, "the golden cadences of poetry," with the tide of feeling, flowing and murmuring as it flows--in short, to take the language of the imagination from off the ground; and enable it to spread its wings where it may indulge its own impulses: "Sailing with supreme dominion Through the azure deep of air," without being stopped, or fretted, or diverted with the abruptnesses and petty obstacles, and discordant flats and sharps of prose, that poetry was invented. It is to common language what springs are to a carriage, or wings to feet. In ordinary speech we arrive at a certain harmony by the modulations of the voice; in poetry the same thing is done systematically by a regular collocation of syllables. It has been well observed, that every one who declaims warmly, or grows intent upon a subject, rises into a sort of blank verse or measured prose.... An excuse might be made for rime in the same manner. It is but fair that the ear should linger on the sounds that delight it, or avail itself of the same brilliant coincidence and unexpected recurrence of syllables, that have been displayed in the invention and collocation of images. It is allowed that rime assists the memory.... But if the jingle of names assists the memory, may it not also quicken the fancy? (WILLIAM HAZLITT: _On Poetry in General_.)