No man had ever heard a nightingale,
When once a keen-eyed naturalist was stirred
To study and define—what is a bird,
To classify by rote and book, nor fail
To mark its structure and to note the scale
Whereupon its song might possibly be heard.
Thus far, no farther;—so he spake the word,
When of a sudden,—hark, the nightingale!…

EMMA LAZARUS, “CRITIC AND POET”