. A poet!--He hath put his heart to school,
Nor dares to move unpropped upon the staff
Which art hath lodged within his hand--must laugh
By precept only, and shed tears by rule.
Thy Art be Nature; the live current quaff,
And let the groveller sip his stagnant pool,
In fear that else, when Critics grave and cool
Have killed him, Scorn should write his epitaph.
How does the Meadow-flower its bloom unfold?
Because the lovely little flower is free
Down to its root, and, in that freedom, bold;
And so the grandeur of the Forest-tree
Comes not by casting in a formal mould,
But from its own divine vitality.

William Wordsworth

http://www.poemhunter.com/poem/a-poet-he-hath-put-his-heart-to-school/