Thomas Wentworth Higginson, Book and heart: essays on literature and life

[34] this other world may be as real as that of the scientific world, but its methods are not traceable, nor are its achievements capable of being duplicated by the mere force of patient will. Keats, in one of his fine letters, classifies the universe, and begins boldly with “things real, as sun, moon, and passages of Shakespeare.” Sun and moon lie within the domain of science; and at this moment the astronomers are following out that extraordinary discovery which has revealed in the bright star Algol a system of three and perhaps four stellar bodies, revolving round each other and influencing each other's motions, and this at a distance so great that the rays of light which reveal them left their home nearly fifty years ago. The imagination is paralyzed before a step so vast; yet it all lies within the domain of science, while science can tell us no more how Macbeth or Hamlet came into existence than if the new astronomy had never been born. It is as true of the poem as of the poet--Nascitur non fit. We cannot even define what poetry is; and Thoreau says that there never yet was a definition of it so good but the poet would proceed to disregard it by setting aside all its requisitions.

Shelley says that a man cannot say, “ ‘I will ’”