In our modern civilization we are apt to consider that a taste for poetry is a mark of high culture, something which belongs exclusively to trained mental fibre and educated perceptions. It causes us, therefore, some surprise when we study the psychology of savage tribes, to find them almost everywhere passionate lovers of verse and measure, of music and song. This fact, well established by the researches of ethnology, was recognized by more than one keen thinker before ethnology was born. In the last century that erratic genius, Hamann, known in German literature as “the magician of the north,” penned the memorable words, “Poetry is the common mother-tongue of the human race,” and insisted that to attain its noblest flights, “we must return to the infancy of the race, and to the simplicity of a childlike faith,” a dictum warmly espoused by the philosophic Herder and by the enthusiasm of the young Gœthe. Later on, that profoundest of psychologists, Wilhelm von Humboldt, reflecting on the problems presented by the origin of languages, expressed his conviction that man as a zoological species is a singing animal, like many birds; that his vocal organs turn to song as their appropriate function with a like spontaneity as his mind turns to thought or his eyes to the light.
If we inquire into the psychological principle which makes rhythm agreeable to the ear, we shall find that this principle is that of _repetition_. I could carry the analysis still further, and demonstrate to you that the physiological principle of all pleasure is expressed in the formula—“maximum action with minimum effort;” and that the nerves of audition are most successfully acted upon in accordance with this law by limited repetitions with harmonious intervals. All metres, all rhythm, all forms of alliteration and assonance, are but varied applications of the principle of harmonious repetition; and the poet, as a poet, as an artist, must be rated, and practically always is rated, by the skill with which he employs the resources of repetition. Lofty thoughts, beautiful metaphors, delicate allusions, these are his extraneous aids, and by no means his exclusive property; but the form is his own, be it quantity, rhyme, alliteration or accent.